KHARTOUM (Reuters) - Negotiators from Sudan’s ruling military council and main opposition coalition have made progress on the sticking points in discussions on the transition from military rule and are set to hold direct talks within 48 hours, an opposition leader said.

The on-off talks on how to run the country after the overthrow of long-time ruler Omar al-Bashir had been halted on Tuesday after the killing of six people at a rally on Monday, at least four of whom were children.

But on Wednesday, Khalid Omar, from the opposition Forces for Freedom and Change (FFC) coalition, said their lower-level technical committees isolated the key points of contention in a constitutional declaration that will set the path from military rule to a new sovereign council.

The main delegations will meet for further discussions within 48 hours, Omar told Reuters, without giving details on what had been ironed out.

African Union mediator Mohamed Hassan Lebatt urged the military council and the FFC to sign the declaration.

He also called for a speedy trial for those responsible for shooting the children.

They were killed when security forces broke up a student protest in El-Obeid, 400 km (250 miles) southwest of Khartoum, opposition-linked doctors said. The teenagers were rallying against fuel and bread shortages, residents said.

The reaction to the killings remained raw. Hundreds rallied on Wednesday in El-Obeid, the capital of North Kordofan state, shouting, “Blood for blood! We won’t accept blood money!” - a chant that has been used for months during the protests that helped bring down Bashir and since.

The Sudanese Professionals Association, a key part of the FFC, strongly condemned the incident and called for mass nationwide protests on Thursday. The SPA spearheaded the protest movement that led to Bashir’s overthrow in April.

The head of the military council, General Abdel Fattah al-Burhan, on Tuesday called the El-Obeid incident “regrettable” and called for a speedy resumption of talks with the FFC.

However, the Sudanese Communist Party, a member of the FFC, opposes negotiating with the military.

“We will not participate in the ongoing negotiations and will not participate in any levels of power and we will fight with the masses,” Mohamed Mokhtar al-Khatib, secretary general of the Sudanese Communist Party, said on Wednesday.

Khatib also called for Bashir and others to be sent for international criminal trial.

Bashir is facing charges in Sudan, including corruption and illegally possessing foreign funds. The first hearing of his trial, scheduled for Wednesday, was postponed to mid-August, a member of his defense team said. He did not attend the hearing.

Bashir’s mother died on Monday and he was allowed to attend her burial.