A South African soldier died Wednesday when his unit in Sudan's strife-torn Darfur region was ambushed while escorting food supplies for a UN agency, an army statement said Thursday.

The South African National Defence Force (SANDF) troops were protecting a convoy of World Food Programme trucks when they came under attack.

"During the exchange of fire, unfortunately one member of the SANDF was fatally wounded whilst another was wounded," the statement said, without commenting on who may have been behind the attack.

The South African army has been deployed in Sudan's strife-torn Darfur since 2008 as part of the joint African Union and United Nation mission.

President Jacob Zuma announced last month that South Africa would withdraw its 850 troops from Sudan as from April 1.

No reasons were given for the withdrawal.

Relations between Sudan and the United Nations have been tense over Khartoum's demands that the 17,000-strong UNAMID peacekeeping mission shut down.