Khartoum: A helicopter carrying four crew members crashed in Sudan's Darfur region on Monday, killing at least two people, a United Nations (UN) spokesman said.

Two more are feared dead after the aircraft crashed after taking off from Nyala, the capital of South Darfur.

It was not clear what caused the crash.

The UN said that the helicopter had been contracted to transport rations to peacekeepers' bases across Darfur.

Medical teams are at the site of the crash.