The trial of ousted Egyptian president Hosni Mubarak is due to resume in Cairo after a three-month break. He was transported to court on a stretcher in a heavily guarded ambulance.

Mubarak is charged with ordering the killings of 850 protesters who died during the uprising that toppled him in February.

Anti-Mubarak protesters gathered outside the court and chanted against the Kuwaiti lawyers who have arrived to defend the ex-president.

Bloggers and activists expressed their concerns about Mubarak's trial on Twitter. Award-winning Egyptian-American journalist Mona Eltahwy, who was arrested and sexually assaulted by the state's riot police, said: "What does Mubarak do when he's not lying on that made-for-TV medical bed?"

Popular blogger Nervana Mahmoud likened Mubarak's fate to Tunisia's ousted president, Zine El Abidine Ben Ali. "Both Ben Ali & #Mubarak were dictators, the difference is one didn't destroy the society's foundations while the other did," she tweeted.

Around 5,000 police officers were on duty around the courthouse. "Word is around 20 protesters outside Mubarak trial. Which would make the police to protester ratio about 250 to 1," freelance journalist Aaron Ross wrote on Twitter.

Yousry Abdel Razek, the head of Mubarak's defence team, said that recent clashes between protesters and security forces in Cairo may prove that other authorities, and not Mubarak himself, gave orders to shoot protesters during the unrest that began in January, Daily News Egypt reported.

Razek said the defence had gathered new evidence to prove that the former president was not guilty.

Mubarak's two sons, Alaa and Gamal, his former interior minister, Habib al-Adly, and six former security chiefs have been accused along with Mubarak of ordering the killings.

Mubarak, 83, could face the death penalty.