The French police are examining what appears to be a suicide bomb belt found dumped on a Paris street in France’s capital.
The suicide bomb belt found is said to resemble belts used by the attackers and was discovered in a suburb which a suspect is thought to have passed through after the attacks.
The US has issued a worldwide travel alert in response to the attacks.
The Belgian capital, Brussels, also remains on high alert and schools and the metro will stay closed on Tuesday.
They are due to reopen on Wednesday but the highest alert level will continue for at least another week.
Authorities fear Paris-style attacks may be carried out in the city, where at least one Paris attacker lived, with Prime Minister Charles Michel warning that the threat remains “imminent”.
The police in Belgium has charged a fourth suspect with terrorism offences related to the deadly attacks on Paris.
This was 10 days after the Islamic State (IS) militant group launched near-simultaneous attacks in Paris that killed about 130 people.
While the French President, Francois Hollande, described the attacks as an ‘act of war’ organised by the militant group, the French Interior Minister, Bernard Cazeneuve, asked European countries to ‘wake up’ to terror threats after it emerged that the suspected Belgian ringleader of the attacks had entered France undetected.
The police in Belgium have charged a fourth suspect with terrorism offences related to the deadly attacks on Paris.
The Federal Prosecutor’s Office said on November 23 that the man, who was not identified, was detained in a series of police raids in Belgium late on the previous day.
Fifteen other people arrested in the raids were released without charge after being questioned.
The prosecutor’s statement said the man had been charged with “participating in activities of a terrorist group and with [a] terrorist attack.”
Of the other five people arrested on Monday morning, two have been released, while “further enquiries” are under way regarding the others, the prosecutor said.
Belgium had already charged Mohammed Amri and Hamza Attou with aiding fleeing Salah Abdeslam, who is suspected of participating in the Paris attacks.
Abdeslam, 26, a Brussels barkeeper whose elder brother blew himself up during the Paris attacks, has been the focus of a manhunt by French and Belgian authorities.
French police said an object that appeared to be an explosives belt was found in a bin in the Paris suburb of Montrouge on Monday. The item is being examined.
Mobile phone data suggest that Salah Abdeslam – whose brother died in the attacks – was in that area late on the night of the attack.
The November 13 coordinated assaults in Paris, claimed by Islamic State (IS) militants, left 130 people dead.
A third, unnamed suspect had also been charged.
The Prime Minister of Belgium, Charles Michel, says the decision to raise the terror alert level in Brussels to the highest level, was taken due to fears that there might be an attack there, like the one that happened in Paris.
Some of the attackers who killed 129 people in Paris lived in Brussels.
Leading suspect, Salah Abdeslam, is believed to have gone back to Belgium and a huge manhunt is underway.
The Brussels metro is closed till Sunday and people have been told to avoid crowds which include shopping centres and concerts.
The authorities have also recommended that large events, including football matches, be cancelled.
The Belgian government will review the security situation in Brussels on Sunday afternoon, Mr Michel added.
Interior Minister, Jan Jambon, had earlier told reporters that the country’s situation was ‘serious’, but ‘under control’, as he arrived for a special security cabinet meeting on Saturday.
Turkish police, nonetheless, said that they have arrested a Belgian man of Moroccan descent on suspicion that he scouted out sites in Paris.
The Belgian authorities have so far charged three people with involvement in the attacks, which Islamic State said it carried out.