South Sudanese rebels said on Friday government forces had attacked their positions a day after the two sides signed a ceasefire deal, but the government denied the accusation.

The agreement reached on Thursday night in neighbouring Ethiopia allowed for a 24-hour window for the ceasefire to take effect, meaning any clashes would not be in violation of an accord which took almost three weeks to negotiate.

But the reports of continuing conflict reflect the deep distrust between President Salva Kiir and rebel fighters, who include those loyal to former vice president, Riek Machar, as well as more autonomous groups.

“Kiir’s forces’ attacks on our defensive positions in Unity and Jonglei states are clear violations of the Cessation of Hostilities Agreement signed in Addis Ababa,” a statement signed by military spokesman, Lul Ruai Koang, said.

He said the rebels had the right to defend themselves with force. But Kiir’s spokesman dismissed the claim SPLA government soldiers had launched any strikes.

“There was no single gunshot anywhere and we hope the rebels will honour their signature,” spokesman Ateny Wek Ateny told a news conference in the South Sudanese capital Juba.

The violence since mid-December, the worst in South Sudan since it won its independence from Sudan in 2011, has killed thousands of people and driven more than half a million from their homes.