Ten people were killed and more than 100 injured in the worst attack on an underground train at the St Michel metro station in Paris in July 1995.

The BBC's Stephen Jessel: "A well-organised network has been dismantled"

The men are charged with possessing weapons, preparing terrorist actions and threatening public order by intimidation or terror.

If convicted, the defendants face up to ten years in prison.

The men are suspected of being supporters of the Armed Islamic Group (GIA) in Algeria.

One of those believed to have played a major role in the bombings, Khaled Kelkal, was shot and killed by police later in 1995.

Khaled Kelkal: Killed by police in 1995

The prosecution is expected to allege that the defendants wanted to punish France for what they saw as support from Paris for the Algerian Government, which has been locked in a bloody confrontation with the GIA.

During the bombing campaign, which also affected the city of Lyon, a total of 180 people were injured.

The BBC's Paris Correspondent, Stephen Jessell, says the authorities believe that with the arrests of the defendants, they dismantled a well-organised network.

A wave of bombings in Paris and Lyon

The group, which is alleged to have had cells in Paris, Lyon and Lille, is believed to have been headed by four men.

One, known only as "Tarek", is thought to have been shot dead in Algeria in 1997. A second is being held in Britain and will be tried in his absence, while the other two will be in the dock.