JUBA (Reuters) - South Sudan, embroiled in a border dispute with its northern neighbour Sudan, said on Sunday at least 21 people died in two days of clashes between the South's army and Khartoum-backed rebels in the South's oil-producing Upper Nile state.
The clash, which erupted on Friday and continued into the next day, took place in Wau, near Malakal, the administrative centre of Upper Nile, a volatile area that borders Sudan and Ethiopia.
"Twenty-one bodies were counted on the ground, some of whom were from the north and some from the south," said Philip Aguer, spokesman for South Sudan's army (SPLA), adding that three militia members and four trucks had been captured.
South Sudan's Information Minister told Reuters on Saturday two SPLA soldiers had died in that attack.
Sudan's army denied Khartoum supported militias in South Sudan and spokesman al-Sawarmi Khalid said Sudan had nothing to do with the clash.
"We have nothing to do what is happening in Malakal. We don't support any militias in South Sudan," he said.
Khartoum and Juba accuse each other of supporting rebel militia to destabilise their opponents, and each denies the other's charges.
Malakal is a base for many U.N. agencies and international aid groups.
Aguer also said the SPLA was pursuing Sudanese-backed militia near Western Bahr al-Ghazal. He said rebels from the Lord's Resistance Army and the Popular Defence Force were responsible for the attack late on Saturday.
"The SPLA is trying its best to clear that area," he said.
Weeks of fighting between Sudan and South Sudan have threatened to escalate into all-out war, despite intense diplomatic efforts to bring the former civil war foes back to the negotiating table.
The African neighbours have failed to resolve a string of disputes over oil revenues, border demarcation and citizenship since the South seceded from Sudan nine months ago.