Seven UN-African Union (AU) peacekeepers were killed and 22 others were wounded, seven of them critically, in an ambush in Sudan's Darfur region on Tuesday, a UN spokesperson said Wednesday.

A joint police and military patrol of the UN-African Union Hybrid Operation in Darfur (UNAMID) was ambushed by unidentified militia in North Darfur, Michele Montas said.

The attackers used heavy weapons and engaged the UNAMID convoy in an exchange of fire for more than two hours, she said.

"The secretary-general condemns in the strongest possible terms this unacceptable act of extreme violence against AU-UN peacekeepers in Darfur," Montas said.

UN Secretary-General Ban Ki-moon called on the government of Sudan "to do its utmost to ensure that the perpetrators are swiftly identified and brought to justice," she noted.

Ban also called on all parties to redouble their efforts to ensure the safety and integrity of the peacekeeping force and reach a comprehensive settlement to the crisis in Darfur as soon as possible.

"The secretary-general reiterates his appeal to the international community to provide all necessary support to the peacekeeping force in Darfur," Montas added.

(Xinhua News Agency July 10, 2008)