Two Darfur rebel chiefs who signed an accord with the Sudanese government have been killed in an insurgent attack near the strife-torn region's border with Chad, the foreign ministry said on Monday.
"The forces of the Revolutionary Front carried out an odious terrorist operation on Sunday, murdering in cold blood the two leaders Mohammed Bashar and Arko Dahiya" who "were on a peaceful mission in the Yamna region on the border with Chad," it said in a statement.
"Their convoy was attacked by the rebel forces of Gibril Ibrahim -- head of the Justice and Equality Movement (JEM) -- who liquidated the two leaders," it added while denouncing the attack as an act of "terrorism".
For its part the JEM, which did not mention the deaths of the rebel leaders, accused the "dissidents who signed a peace agreement with the government" of attacking its members in areas under its control in North Darfur.
"After the battle, all their vehicles, which were full of weapons and ammunition... were seized," the movement said in a statement, charging that the "militia came with the support of Chad".
Bashar's faction signed a peace deal with Khartoum in April, becoming only the second group to join a 2011 pact agreed between the government and the Liberation and Justice Movement, an alliance of rebel splinter factions.
The African Union-United Nations Mission in Darfur condemned Sunday's killings "in the strongest possible terms".
UNAMID's Joint Special Representative Mohamed Ibn Chambas said Bashar's faction had "clearly stated its preference for a peaceful resolution to the conflict in Darfur when it joined the Doha Document for Peace in Darfur on 6 April in Doha".
Chambas urged all sides in the fighting in Darfur "to cease hostilities, respect international humanitarian law and engage fully in the peaceful settlement of the conflict".