Egyptian prisoners killed in police custody

Thirty-six prisoners were killed Sunday in Egypt while in police custody. Authorities said the men died during an attempted prison break by armed supporters of the Muslim Brotherhood in which one officer was seriously wounded. But there were numerous counter claims, including the suggestion that not all the prisoners were members of the Islamist group and that they died from asphyxiation by tear gas while locked in the back of a police truck.

The deaths of the prisoners, captured during the fierce fighting in recent days around Cairo's Ramses Square, came as Egypt's army leader Gen. Abdel Fattah el-Sisi vowed that the military would not tolerate further violence after four days of nationwide clashes left nearly 900 people dead and thousands more injured.

Al Jazeera's Bernard Smith, reporting from Cairo, quoted a source as saying that the prisoners had, in fact, been arrested in the clear out of the Fateh mosque on Saturday.

The detainees were part of a prison-truck convoy of some 600 people heading to Abu Zaabal prison in northern Egypt, officials told The Associated Press. Prisoners in one of the trucks rioted Sunday night and managed to capture a police officer inside, the officials said.

Security forces fired tear gas into the truck in hopes of freeing the badly beaten officer, the officials said, before adding that those killed died from suffocating on the gas.

The officials spoke on condition of anonymity because they were not authorized to speak to journalists. However, the officials' version of events contradicted reports about the incident carried by state media.

The official website of Egyptian state television reported that the deaths took place after security forces clashed with armed men near the prison and detainees came under fire while trying to escape. The official MENA state news agency also said the trucks came under attack from gunmen.

State media also said all those killed and the gunmen belonged to the Muslim Brotherhood, the organization that deposed President Mohamed Morsi hails from. The officials who spoke to AP said some of the detainees belonged to the Brotherhood, while others didn't.

The differences in the accounts could not be immediately reconciled.

Police arrested more than 1,000 anti-coup protesters since Wednesday, when they and the military launched a crackdown on supporters of the ousted president.

Al Jazeera and news wires