At least 43 people were killed in fighting between armed groups and government forces around the northwest South Sudanese town of Wau last week, a government official said on Tuesday.
Thousands fled the clashes in the world's newest country, still hit by violence almost five years after securing its independence from former civil war foe Sudan, and months after a peace deal with rebels inside its own borders.
Government forces had battled fighters loyal to Ali Tamin Fatan, a militia leader trying to control territory further west near the border with Central African Republic, government spokesman Makuei Lueth told reporters.
“So far up to this morning the report which I got is that there are 39 (civilian) bodies and another four belong to police," Lueth said. Numbers could rise, he added, as there were currently no casualty figures from the army.
Lueth said Fatan was trying to carve out an Islamist state but added that his force included members of the notorious Lord's Resistance Army, a nominally Christian group that fought a violent insurgency in neighbouring Uganda and has launched attacks across the region. He was not immediately available to give further details.
Impoverished South Sudan has been plagued by fighting between a range of armed groups, often along ethnic lines, vying for control over grazing land and oil reserves.
Lueth accused Sudan of backing the rebels, a charge often levelled at the Khartoum government which regularly dismisses such allegations and accuses South Sudan of supporting insurgents in its territory.
The United Nations said late on Monday that around 12,000 people had sought refuge in a cordoned-off area around its base in Wau.