Four people have been killed after gunmen attacked a market and set fire to a police station during several days of violence in Sudan's Darfur region, international peacekeepers have said.

Gunmen surrounded a camp for displaced people in Kassab in North Darfur state, burnt down a police station and looted the main market, African Union/United Nations peacekeepers UNAMID said in a statement on Monday.

UNAMID said it had received reports that four people had been killed and others injured since the first incident last Wednesday.

Since then more looting and fighting between government forces and gunmen had taken place over several days in the Kassab camp as well as the nearby Kutum town and Fataborno camp.

Banditry, inter-ethnic fighting and clashes between rebel groups and government forces continue in Darfur, in Sudan's far west, nearly a decade after rebels first rose up against the Arab-dominated Khartoum regime.

Mainly non-Arab rebels took up arms in Darfur in 2003, complaining the central government in Khartoum had neglected the remote western region.

Violence has since subsided from its peak, but law and order has collapsed in many parts of the vast territory and clashes have continued to erupt between rebels and government forces.

Following the most recent incidents, UNAMID "requested the government investigate the reported attacks and abuses on civilians and the destruction and looting of equipment belonging to humanitarian agencies," it said on Monday.

Soldiers killed

Sudan's army said two soldiers were killed and two wounded when troops moved into Kutum to restore order, the state-linked Sudanese Media Centre said late on Sunday. It said the situation was now under control.

Sudan said on Wednesday gunmen had killed a local government official in Kutum.

The official, Abdelrahman Mohammed Eissa, the head of North Darfur's Al-Waha district, died from gunshot wounds after an ambush and theft of his car in Kutum, official media reported.

The day after the killing, armed men began looting and ransacking a compound of the UN's World Food Programme in Kutum, WFP spokeswoman Amor Almagro said.

"Our office and guest house were looted," with furniture, fuel, computers and other items stolen, she said, adding WFP staff hid and were unhurt during the looting which continued for about 12 hours.

"Since the security situation remains tense and unpredictable we have decided to suspend our operation until the situation calms down," she said.

Sudan's government signed a Qatar-brokered peace deal with small rebel groups a year ago but the main rebel groups have refused to join.

The International Criminal Court has indicted Sudanese President Omar Hassan al-Bashir and issued an arrest warrant for Defence Minister Abdel Raheem Muhammad Hussein for war crimes in Darfur.