Sudan's army on Friday said it clashed with fighters from two rebel factions in Darfur in a four-hour fight that left 21 people dead.

A string of failed ceasefires and accords has failed to stop the fighting in the remote western territory where mostly non-Arab rebels took up arms against the government in 2003.

The military said forces from the rebel Justice and Equality Movement (JEM) and the Sudan Liberation Army (SLA) loyal to Minni Minnawi ambushed its men on a road between the capital of South Darfur state Nyala and the capital of North Darfur state El Fasher on Thursday evening.

"We killed 13 JEM and SLA [...] and also we lost eight men from the Sudanese army," Sudanese army spokesman Al-Sawarmi Khaled said on Friday, adding his men routed the insurgents.

Al-Tahir al-Feki, a senior JEM official based in Britain, said he was aware of the fighting but was still waiting for a detailed report from commanders on the ground.

Khaled said he thought the rebels were reacting to a recent statement from the country's minister of defence that a large part of the region was now clear of rebels. "This was their reply," the spokesman said.

The fighting took place between the villages of Menawashi and Kidnir in South Darfur, he said.

The violence in Darfur has died down from the mass killings reported in the early days of the conflict. But there have been sporadic clashes between the army and rebel forces, particularly since JEM walked out of floundering peace talks last year.

JEM and the SLA accused Sudan's government of neglecting the development of the region when they first launched their revolt. Khartoum set out to crush the uprising with its own troops and allied mostly Arab militias.

The International Criminal Court (ICC) has issued arrest warrants for Sudan's president Omar Hassan al-Bashir, accusing him of masterminding genocide during the counter-insurgency campaign.

Separately UNAMID reported it had helped move two aid workers for the U.S.-based Catholic Relief Services (CRS) from a remote location in West Darfur after the government reported unspecified "threats" had been made against them.

Armed men abducted three Bulgarian helicopter crew working for the UN World Food Programme in West Darfur last week, the latest in a series of kidnappings targeting humanitarian staff.

(Source: Reuters)