Zarqawi admitted the plot, but denied the use of chemical weapons

Zarqawi and three of the other defendants were condemned in absentia. He already faces two death sentences in Jordan for other convictions.

Alleged mastermind Azmi al-Jayousi was in court. His lawyers said he was tortured to extract a confession.

The foiled April 2004 attack could have killed thousands, Jordan officials say.

Suicide bombers were to drive trucks loaded with explosives and toxic chemicals into the country's intelligence headquarters.

Deadliest attack ever

After the sentencing, the accused shouted that the judges were tyrants.

"Bin Laden's organisation is rising and we will be back!" they said.

When the men were arrested, the authorities said the attacks could have killed tens of thousands of people in what the BBC's Jon Leyne in Amman says would have been the deadliest terrorist attack ever staged.

The defence argued that the men were caught with only a relatively small quantity of battery acid, not the ingredients for a massive chemical bomb.

They said that Jayousi was tortured in prison for two weeks in order to produce a confession.

An audio tape attributed to Zarqawi acknowledged his group was behind the plot, but denied that chemical weapons were to be used.