Fighting has erupted in South Sudan’s oil-rich Upper Nile state, breaking the ceasefire signed by rebels and the government in January, representatives of both sides said on Tuesday.

Upper Nile capital Malakal is under the control of rebels, who are now marching toward the biggest oil fields in the region, a rebel spokesman told DPA in Nairobi.

“There were pockets that we did not control, but we overcame these pockets of resistance, so our forces are in full control and are just consolidating our gains,” rebel spokesman Lul Ruai Koang said in Addis Ababa.

Government Army spokesman Philip Aguer confirmed that fighting was going on in Malakal. “It is too early to tell who is in control of the town,” he said.

Malakal residents said clashes started in the morning and that many people fled to a United Nations compound near the airport.

Representatives of President Salva Kiir and rebel leader Riek Machar signed a ceasefire on January 23, and confirmed last week that they would launch peace talks.

But the truce has been fragile from the beginning, with sporadic fighting reported especially in the north of the country.

Both sides have accused each other of breaking the ceasefire.

The peace process has stalled over Mr. Kiir’s refusal to release four Machar supporters whom he accuses of plotting a coup.

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