Fighting has broken out between the South Sudanese military and rebel forces in the capital of oil-producing Upper Nile state. Each is blaming the other for the hostilities.
Army spokesman Philip Aguer told VOA rebel forces attacked government positions in the north of Malakal early Tuesday and fighting continued into the day.
Both sides had agreed to stop fighting as part of a ceasefire deal signed last month in the Ethiopian capital Addis Ababa.
Aguer said the latest violence compromises that agreement and the continuation of talks.
“They are attacking Malakal while people are discussing in Addis. So this is a serious violation,” he said.
Clashes erupted across the country in December, after an outbreak of violence in the capital and government accusations of a coup attempt, allegedly led by former Vice President Riek Machar.
The city of Malakal was seized by rebel forces during weeks of fighting that followed, but was reclaimed by government forces in January.
Malakal is the capital of Upper Nile state, which produces the bulk of South Sudan's oil, the lifeblood of the country's economy.
Speaking to VOA by telephone from Addis Ababa, opposition forces spokesman Lul Ruai Koang blamed the government for the resumption of fighting in the city.
He said the rebels responded to government attacks Tuesday and pursued military forces back to their strongholds near the airport north of the city.
“We are not trying to reclaim control," Koang said. "We had actually been in partial control of Malakal. What had been a problem was that they had been attacking us from these places, harassing civilians and stealing their property and food. So we thought it was time for us to clear these pockets of resistance.”
Talks were to resume in Addis Ababa last week, but were postponed due to a rebel demand for the release of four remaining political detainees arrested early in the crisis.
Thousands of people have been killed in the conflict, and more than 850,000 have been displaced.