Egypt's former intelligence chief who was also briefly vice president, Omar Suleiman, began giving testimony on Tuesday at the trial of ousted President Hosni Mubarak, who is charged with conspiring to kill protesters, state television reported.

Suleiman is among a list of senior officials or former officials to be called as witnesses in the trial. Their testimonies could be decisive in determining whether Mubarak, who ruled for three decades, is innocent or guilty.

Judge Ahmed Refaat who called the witnesses to attend ordered a news blackout for reasons of national security, so their testimonies will not be made public.

Field Marshal Mohamed Hussein Tantawi, who heads Egypt's ruling military council, and another top general were to given testimony on Sunday and Monday. The hearings were postponed to September 24 and 25 after they said they were busy with security issues after protesters stormed the Israeli embassy in Cairo.

Suleiman was made vice-president in the final days of Mubarak's rule in a bid to quell the protests, but demonstrators stayed out on the streets and Mubarak was forced out of office on February 11.

The move to bar the media has angered many Egyptians who have demanded a transparent trial. Images of the first two of Mubarak's trial sessions were broadcast live. Cameras have since been barred but journalists attended other sessions.

Mubarak, 83, has been attending the trial hearings that began on August 3 on a stretcher and inside a defendants' cage in the Cairo court. He has been hospitalised since April, when he was first questioned.