"There has to be an international investigation immediately," Minni Arcua Minnawi, the head of the SLA who became presidential adviser in Khartoum.
"We are committed to the peace and the ceasefire but we want the government to not repeat any action like this."
FORMAL COMPLAINT
The attack on Muhajiriya, Minnawi's main town, was the latest in an upsurge of violence in southern Darfur after the worst attack on African Union peacekeepers since they deployed, killing and wounding at least 20 and destroying their base in Haskanita.
Two aid agencies working in the town as part of efforts to quell one of the world's worst humanitarian disasters evacuated 29 staff after they were trapped by the fighting.
Minnawi said his movement had written a formal complaint to the United Nations and African Union about the assault.
The army blamed tribal clashes between the Zaghawa and Maaliya in the area. Minnawi's party accused Khartoum earlier this year of arming the Arab Maaliya tribe.
"This is the behaviour of the government. They will never commit to any agreement," Minnawi told Reuters from Darfur.
"This will have a negative effect on peace talks."
Minnawi is in Darfur to meet rebel factions who rejected the last deal to persuade them to attend the talks, mediated by the United Nations and the African Union, and unify their ranks.
In a report made public on Wednesday, U.N. Secretary-General Ban Ki-moon said he was "extremely concerned" about the "unacceptable" violence in the vast region, which he said was "not contributing to an atmosphere conducive to the peace talks".
He said the attack on the AU peacekeepers "confirms that the ... force which will be deployed to Darfur must be sufficiently robust to defend itself from spoilers and protect civilians from attack". A 26,000-strong AU-U.N. peacekeeping force is planned.
Mostly non-Arabs took up arms in early 2003 accusing Khartoum of neglect. International experts estimate 200,000 have died and 2.5 million driven from their homes in 4-1/2 years of fighting.
Khartoum puts the death toll at 9,000 and says the West has exaggerated the conflict in Darfur.
