Former Egyptian President Hosni Mubarak is seen in the courtroom for his trial at the Police Academy in Cairo, in this still image taken from video August 3, 2011. Mubarak was wheeled into a courtroom cage in a hospital bed on Wednesday to face trial for killing protesters.If convicted, Mubarak could face the death penalty.[Photo/Agencies]

CAIRO -- Former Egyptian president Hosni Mubarak's trial started Wednesday in Cairo's Police Academy.

Mubarak, who was transferred to Cairo early Wednesday morning from the Red Sea resort Sharm El-Sheikh, appeared on a stretcher in the dock.

He stood trial with his two sons, ex-interior minister Habib Adli and six police officers. The businessman Hussein Salem was tried in absentia.

The defendants were accused of misusing of national funds, exporting gas to Israel at a very low price and ordering the killing of protesters.

The trial began around 10 a.m. (0800 GMT) and was broadcasted by state TV.

Clashes occurred outside the trial venue between Mubarak's supporters and protesters, who came to the trial site at 3 a.m. ( 0100 GMT) and later threw rocks at each other.

Police have put barriers to separate the two groups, trying to calm down the crowds after the trial began.

During the trial, Mubarak's lawyer called for separate trials.

Mubarak, 83, was forced to step down in February after 18 days of popular protest. A military council took over power later and promised to hold parliamentary and presidential elections.