Security forces fired tear gas to disperse dozens of students demonstrating against the ruling military council at a financial academy in the heart of Sudans capital Khartoum on Thursday as the Sudanese protest movement said it received a new, joint proposal from the African Union and Ethiopia for a solution to the country’s crisis. Dozens of lawyers also gathered outside the main courthouse complex in Omdurman, Khartoums twin city, calling for civilian rule and for people to join mass demonstrations planned for Sunday. They chanted: "Freedom, peace, and justice. Civilian (rule) is the peoples choice." Demonstrations in Khartoum have become rare since security forces broke up a sit-in outside the Defense Ministry on June 3, leaving more than 100 people dead, according to medical sources. The sit-in had become the focal point of protests against former president Omar al-Bashir and the military council that ousted him on April 11. The US envoy to Sudan met Thursday with Arab League chief Ahmed Abuel-Gheit in Cairo after he concluded a four-day visit to the Sudanese capital. Donald Booth expressed Americas support for the Sudanese protest movement and called for a civilian-led government amid stalled negotiations between the pro-democracy leaders and the ruling military. The US Embassy in Khartoum said in a statement Wednesday that Booth urged the military to stop attacking protesters and allow for an independent probe into the crackdown. In recent weeks, Ethiopia and the AU have been mediating between the military council and the pro-democracy movement demanding civilian rule. Talks collapsed when Sudanese security forces cleared the protest camp. Protest leaders, represented by the coalition Forces for Declaration of Freedom and Change, said in a brief statement they have a draft of a proposed agreement with the military council, based on on a previous initiative from Ethiopia for a power-sharing agreement. Ethiopias initiative was built on previous agreements between the military and the protesters. It also tackled the disputed makeup of the sovereign council, proposing a 15-member body with eight civilian and seven military members, with a rotating chairmanship. All the civilians in the proposed council would come from the FDFC, except for one independent and "neutral" appointee, according to a copy of the proposal obtained by The Associated Press. The Ethiopian proposal also stipulates that the military would chair the council in the first 18 months, and the FDFC the second half of the transition. The military council, however, had refused to agree to that, saying the initiative was to pave the way for resuming talks with the FDFC, "not to offer proposals for solutions." It asked Ethiopia to present a joint proposal with the AU, which it said had handed the military a separate transition plan.