The 65-year-old Kamto was jailed in January after his party staged several peaceful marches challenging that result.
Released in October, he has since tried three times to hold marches but was denied permission each time.
The West African country was for years considered relatively stable, but it has been shaken by a two-year-old separatist uprising in the west as well as attacks by the jihadist group Boko Haram in the north.
Biya, under international pressure, held a national peace dialogue last month during which he announced the release of 333 detainees linked to the separatist crisis.
He also ordered the release of 102 opposition activists arrested in 2018 during protests over his re-election.
Contacted by AFP, MRC general secretary Christopher Ndong said the party needed time to evaluate the news of fresh elections before responding.
“We have asked that certain preconditions be met, such as the revision of the electoral code,” he said.
The main opposition party in parliament is still the Social Democratic Front (SDF), even though its candidate in last year’s presidential election garnered only 3.35 percent of the vote, coming in fourth.
Contacted by AFP, the party was not immediately willing to say whether it would take part in next year’s elections.
Late last month, Washington announced it was stripping Cameroon of its preferential trade status because of its poor rights record.
Cameroon’s main opposition leader Maurice Kamto walked free from jail Saturday after a military court ordered his release at the behest of veteran President Paul Biya.
The surprise conciliatory gesture comes as the president is facing a number of domestic crises and international criticism over political freedoms.
“We are here today thanks to your constant support,” Kamto, who had spent nine months behind bars, told hundreds of supporters who gathered to greet him.
“I saw you even when you couldn’t see me.”
He announced a “new chapter in our struggle”, adding that “if some people think that our liberation means the end of our struggle they have understood nothing”.
The struggle would be “peaceful”, he said before being driven away surrounded by a dozen-strong escort of klaxon-blaring vehicles.
Kamto, 65, was arrested in late January after months of peaceful opposition protests over the results of the October 2018 election.
He went on trial with dozens of others in a military court in September on charges of insurrection, hostility to the motherland and rebellion — crimes which could be given the death penalty, though this is no longer carried out in Cameroon.
Biya, 86, has ruled Cameroon with an iron fist for nearly 37 years.
On Friday he announced he had ordered prosecutions to be dropped against “some” opposition leaders, including a number from the main Movement for the Rebirth of Cameroon (MRC) which Kamto leads.
More than 100 people in detention are also now set for release “if they have not been detained for anything else”, the military court said.
They include Biya’s former economic advisor Christian Penda Ekoka, lawyer Michele Ndoki and rapper Valsero, well known for songs critical of the ruling establishment.
Amnesty International called Biya’s decision “a welcome step towards ending the long repression of dissenting voices in Cameroon”.
But the organisation also called on authorities to “go further by releasing all other individuals arbitrarily detained for having exercised their right to freedom of expression and peaceful assembly”.
As the opposition leader arrived at his home in a residential neighbourhood of Yaounde following his release, he was met by dozens of cheering, dancing young people.
“Maurice Kamto, save us,” the crowd chanted.
Most of those gathered were under 30 and — like around 75 percent of the population — would not have known another leader than Biya.
“We are tired of this system that has been in place for 37 years,” said one protester, Abraham. “We want alternance in power. We want a new momentum for our country.”
‘Crises and conflicts’
Biya’s shock announcement Friday came on the closing day of crunch talks aimed at easing a bloody crisis in Cameroon’s anglophone regions, which were shunned by the main separatist leaders.
The talks also ended with a proposal to give more autonomy to the English-speaking regions, where a two-year armed campaign for independence has been met with a brutal crackdown and cost nearly 3,000 lives, according to the International Crisis Group.
In addition, Biya had Thursday announced the shelving of an investigation and the release of 333 people detained during the crisis.
The two areas in western Cameroon — the Northwest Region and Southwest Region — are home to most of the country’s anglophones, who account for about a fifth of a population that is overwhelmingly French-speaking.
A presidential statement Saturday said that “the head of state reaffirms his determination to pursue relentlessly his efforts seeking ways and means to resolve peaceably the crises and conflicts confronting our country”.
The apparent seachange in Biya’s approach comes after months of intransigence and follows international pressure.
Washington indicated in March that Yaounde would do well to free Kamto — a sentiment repeated since by the European Union and also France.
“The president is well aware that Cameroon is at a crossroads as it is dealing with important crises,” Richard Makon, an expert on Cameroon politics, told AFP.
UN Secretary-General Antonio Guterres said in a statement on Saturday that he “encourages the Cameroonian authorities to continue to adopt further confidence-building and reconciliation measures”.
Cameroon opposition leader Maurice Kamto, who claims to have been cheated out of the presidency in elections last year, was arrested in the country’s economic capital Douala on Monday, a senior party member said.
The arrest is the latest political turbulence to hit the West African country and comes after several recent eruptions of violence over the October vote, which saw Kamto come second behind Paul Biya, who has ruled for more than three decades.
“Mr Kamto was arrested at the home of (supporter) Albert Dzongang,” said Emmanuel Simh, vice-president of the opposition Movement for the Rebirth of Cameroon (MRC), confirming information from a source in Douala.
Following Kamto’s arrest, around 300 people gathered outside Dzongang’s house, according to an AFP reporter, flanked by about 50 police officers. Shots were fired into the air to disperse the crowd.
The authorities did not respond to an AFP request for information.
Veteran leader Biya won a seventh consecutive term in the October election, which was blasted by the MRC as an “electoral hold-up”.
Kamto, who has continued to claim he was the rightful winner, won 14.23 percent of the vote to place second, according to the official figures, but his party has held sporadic protests since then to dispute the result.
On Saturday 117 people were arrested during protest marches in several towns.
The MRC was holding a crisis meeting late Monday in response to the arrests, Simh told AFP, adding that Dzongang and Christian Penda Ekoka, an economist, were also arrested in Monday’s police raid.
Kamto’s former election campaign head Paul-Eric Kingue and rapper Valsero were among those detained over the weekend.
The Cameroon government has looked to dissuade Kamto’s party from demonstrating, claiming that the opposition leader was an “outlaw” for not accepting the election results.
In France dozens of protesters broke into Cameroon’s Paris embassy on Sunday, vandalising portraits of Biya, according to witnesses.
Police forced them out of the building two hours later and onto the street, where they continued their protest outside the embassy.
Biya has ruled the West African country since 1982 with support from the army, government administrations and the Cameroon People’s Democratic Movement (RDPC) that he created in 1985.
Cameroon police on Saturday arrested around 50 supporters of opposition figure Maurice Kamto during an unauthorised march in Douala, his spokesman said.
“Mass arrests of activists (Mrs Michele Ndoki and around 50 others) and of supporters demonstrating peacefully today,” the spokesman, Olivier Bibou-Nissack, said in a Facebook post, referring to one of Kamto’s lawyers.
The protesters were arrested during a rally in Douala, the country’s economic capital.
Among them was a journalist who was covering the event, sources said.
Kamto has rejected the official outcome of this month’s presidential election, in which he was one of seven candidates seeking to unseat President Paul Biya who has ruled Cameroon for 35 years.
Kamto came second with 14.23 percent the vote, against 71.28 percent for 85-year-old Biya who has spent 35 years in power.
Ndoki is one of Kamto’s lawyers who protested before the Constitutional Council against what she called “massive and systematic fraud” during the election.
Bibou-Nissack said the headquarters of Kamto’s party, Movement for the Rebirth of Cameroon (MRC), had been vandalised.
The building was cordoned off by police who stopped anyone from approaching, an AFP journalist said.
On Friday, government minister Paul Atanga Nji warned that “any attempts to disturb the public order will be met with the greatest firmness”.
Cameroon authorities were not available for comment Saturday afternoon.
Cameroon’s Interior Minister Paul Atanga Nji warned Tuesday that “scoring a goal” is not “winning the match” after an opposition leader used a football metaphor to claim victory in presidential polls.
Maurice Kamto, candidate of the Movement for the Rebirth of Cameroon (MRC) party, said Monday he “was charged with taking a penalty, I took it, and I scored”, proclaiming himself victor of weekend polls.
He gave no evidence for his claim.
Sunday’s vote, in which Kamto headed a partial opposition coalition, was marred by violence in restive anglophone regions as well as low turnout and difficulties staging the ballot in the conflict-torn areas.
“Even if you score a penalty, you don’t necessarily win the match at the end,” Atanga Nji told AFP, adding that Kamto’s announcement was a “non-event”.
By law each polling station must submit its results, after verification by the Elecam electoral commission, to the Constitutional Court which is responsible for announcing the official final tally within 15 days of the vote.
But a raft of unofficial results from Cameroon’s nearly 25,000 polling stations have already begun to circulate on social media.
Ahead of the polls in which 85-year-old President Paul Biya sought a seventh term, Kamto warned he would not accept any result tainted by fraud.
The government has called Kamto an “outlaw” for announcing his own result.
“I have received a clear mandate from the people and I intend to defend it until the end,” he said at a media briefing in Yaounde on Monday.
But Atanga Nji accused Kamto of creating “an unacceptable mess”.
“He says he’ll go all the way, but he won’t even have time to get going… and no one will follow him,” Atanga Nji said.
The candidate of the main opposition Social Democratic Front (SDF) party, Joshua Osih, said Monday it was “a bit premature to be giving results” and called on his seven fellow candidates to “respect the law”.
The youngest of the nine candidates, 38-year-old jurist and journalist Cabral Libii of the opposition Univers party, warned against election fraud.
“If our victory is established, I will by no means allow it to be stolen by anyone,” the social media-savvy candidate told reporters on Tuesday.
The US embassy in Yaounde meanwhile called “on all parties to wait until the official results are announced before making pronouncements about the supposed winner,” in a post on its verified Facebook account.
Kamto, a former junior justice minister, was backed by rival candidate Akere Muna just before polling day, creating the first opposition electoral union since 1992.