Sudan carried out fresh helicopter attacks in Darfur on Tuesday and worsened an already desperate humanitarian situation while Arab militia targeted refugees trying to escape the conflict, the United Nations said.

"Fresh violence today (Tuesday) included helicopter gunship bombings by the Sudanese government and Janjaweed (militia) attacks in South Darfur," the U.N. Office for the Coordination of Humanitarian Affairs said in a statement from Geneva.

"The violence has already led to more displacement," the statement said, adding: "Janjaweed attacks on internally displaced persons in and around IDP settlements continue to be reported in all three Darfur states," it added.

Civilians have previously said Sudan used helicopters and other military aircraft to attack villages in Darfur, but there have been fewer reports of such attacks since rebels and the government signed a cease-fire in April.

In Khartoum, Sudanese officials were not immediately available for comment. Sudan's ambassador to Britain, Hassan Abdin, told Channel Four News his government was committed to disarming the Janjaweed militias.

Talking generally, the ambassador said: ""Sudan has already been delivering on some of the promises it made. There is no bombing now, it has stopped long ago. After the cease-fire in April, the Sudanese government observed the cease-fire."

Under a joint plan agreed with the United Nations last week, Sudan said it would establish safe areas for the displaced and cease military operations by its troops and rebels there.

Source: CD/Agencies