A senior police officer has testified in the trial of former Egyptian President Hosni Mubarak that he was not aware of any order to shoot live ammunition at protesters in Cairo's Tahrir Square during the uprising that led to the president's ouster.

General Hussein Moussa said at the resumption of Mr. Mubarak's trial Monday that police used tear gas and rubber bullets. He said some police resorted to live ammunition to protect police stations but were not instructed to do so.

Mr. Mubarak has pleaded not guilty to charges that he ordered the killing of 850 protesters during the uprising that drove him from power earlier this year. He is also facing charges of corruption and abuse of power.

The officer's testimony bolsters claims by Mr. Mubarak's backers that he did not orchestrate the violence.

Some people following the case reacted angrily to the testimony on Monday and claimed it was changed due to pressure from the defense.

Brawls inside and outside the court caused temporary chaos. A supporter of Mr. Mubarak lifted a photo of him up in the courtroom, angering relatives of victims and starting a fight that even some of the lawyers jumped into.

Outside the court security forces clashed with protesters, including some who threw stones at police.

The court will hear testimony from three other police officers. Mr. Mubarak arrived at the trial on a stretcher.

The proceedings are not being televised, unlike two previous sessions that showed Mr. Mubarak lying on a hospital bed inside the courtroom's large metal cage with his two sons at his side. The judge presiding over the case ordered an end to the live broadcasts last month.

The former leader's sons, Alaa and Gamal, have denied separate corruption charges against them.

Mr. Mubarak is being tried along with former interior minister Habib al-Adly and six deputies, who are accused of giving orders that led to the killing of protesters.

He is the first Arab leader to face trial in person since the so-called “Arab Spring” of popular revolts swept across much of North Africa and the Middle East this year.