The trial is being held in a maximum security prison

The four men and a woman are accused of being leaders of the People's Revolutionary Struggle (ELA).

The group has claimed responsibility for two murders, 80 assassination attempts and 76 bomb attacks.

The trial is being held under tight security by a special anti-terrorism tribunal without a jury.

It is part of a police crackdown on radical groups in the face of intense international pressure to improve security ahead of the Athens 2004 Olympic Games in Athens.

The five suspects stand accused of having carried out a bomb attack on a police van in 1994, in which an officer was killed.

They are also charged with having instigated the assassination of a public prosecutor in 1989.

Further charges are related to dozens of bomb attacks on Greek and foreign targets in Greece.

Other charges were dropped because of a 20-year statute of limitations.

They were originally brought in connection with attacks dating from before 1983, including the assassination of a junta collaborator,

Christos Tsigaridas has admitted being a member of ELA

Confession

One of the suspects, 64-year-old civil engineer Christos Tsigaridas, has told police he was a member of ELA.

The other four, including the mayor of a small Aegean Sea island, have denied all charges.

If convicted, all five face a sentence of life imprisonment.

Two months ago, the same court in Korydallos maximum security prison handed down life sentences to members of the left-wing extremist group November 17 for murder, bombings and robberies carried out during the same period.

The radical left-wing ELA was formed in 1975, one year after the fall of Greece's military junta.

Like November 17, ELA was born out of opposition to the US-backed junta that ruled Greece from 1967 to 1974.