Several army recruits reportedly needed medical treatment after a punitive training session in Oudtshoorn.
The UN-African Union peacekeeping mission said on Monday that the attack took place on Sunday near Mellit, in North Darfur state, and resulted in an exchange of fire.
UN chief Ban Ki-moon condemned the attack and called on the Sudanese authorities to investigate and bring the perpetrators to justice as soon as possible, his spokesperson said.
Darfur erupted into conflict in 2003 when ethnic minority rebels in the western region launched a campaign against the Arab-dominated Khartoum government, complaining of marginalisation.
President Omar al-Bashir unleashed a brutal counter-insurgency using Arab militia as well as regular troops.
Rebels and militia alike have since splintered into a myriad of factions patrolling their own turf.
In recent years, insecurity has deepened further with rising criminality and inter-tribal conflict over land and resources. – AFP