KHARTOUM, Sudan -                                                      The head of Sudan's ruling military council said on Tuesday there must be immediate accountability over an incident in which at least four schoolchildren were shot dead at a protest.

Abdel Fattah al-Burhan is due to make a televised address to the nation about Monday';s incident at 8 p.m. (1800 GMT), Sudan TV said, although the nature of his comments was not yet clear.

The children’s deaths came at a time of heightened tension between Sudan’s military rulers and the main opposition coalition, which called for nationwide protests in response -- although the turnout was limited.

More talks between the two sides on the transition from military rule to a new sovereign council were due to take place on Tuesday but were postponed after the shooting, a pattern that has happened repeatedly after bouts of violence, London South East, reports.

“What happened in El-Obeid is a regrettable and upsetting matter and the killing of peaceful citizens is unacceptable and rejected and a crime that requires immediate and deterrent accountability,”Burhan was quoted by state news agency SUNA.

The pupils and an adult were shot dead when security forces broke up a student protest in El-Obeid, some 400 km (250 miles) southwest of Khartoum, opposition-linked doctors said.

The teenagers were rallying against fuel and bread shortages, residents said.

The Forces of Freedom and Change (FFC) coalition of opposition groups accused military and paramilitary forces of opening fire on the high school pupils.

However,  FFC  has called for those responsible for the deaths to be held accountable and for the military council to immediately agree the details of a new transitional authority.

The military council has been ruling Sudan since generals ousted veteran president Omar al-Bashir on April 11.

Long-stalled negotiations over the path towards the transition collapsed altogether when security forces broke up a protest camp outside the Defence Ministry on June 3, killing dozens of people.

However, Ethiopian and African Union mediators were able to bring them back to the table, and they signed a political accord on July 17. They have been wrangling over the details of a constitutional declaration since then.