Stathis said the gunmen had aimed at the guard post outside the police station.

At least 10 shots were fired, but the officer on duty fell to the floor as soon as he saw flashes from the attackers' weapons and was not wounded, Stathis said.

He said authorities were conducting ballistics tests on the 9mm bullet casings found at the scene to determine whether they matched any of the automatic rifles that the Revolutionary Struggle is known to use.

'Troubling incident'

Stavros Mavroidakos, the deputy head of a police officers' association, said the attack was troubling.

"Clearly, there is an effort to take the life of policemen, I don't think anyone can doubt that," he said.

Last month, gunmen suspected to be members of the Revolutionary Struggle, shot and seriously wounded a riot policeman in central Athens in an attack against a police unit guarding the culture ministry.

Revolutionary Struggle attacked the United States embassy in Athens in 2007 [EPA]
The group is possibly best known for firing a rocket-propelled grenade into the United States embassy in Athens in 2007.

Washington offered a $1m reward for information leading to the capture of Revolutionary Struggle members.

Stathis said a local newspaper had received a claim of responsibility after Tuesday's attack, but he did not name any group and said officers were investigating.

Revolutionary Struggle, which first appeared in 2003, issued a statement after the January 4 wounding of a police officer in Athens vowing to continue with the attacks.

It said its actions were a response to the fatal police shooting of a 15-year-old boy in Athens on December 6 that sparked the worst riots Greece had seen in decades.

"The December riots were a good message for what will follow," the group had said in its nine-page statement.

Violent history

Revolutionary Struggle also claimed responsibility for shooting at a riot police bus on December 23 and for the attempted bombing of the Greek offices of oil company Royal Dutch Shell, also in Athens, on October 24.

Greece has been troubled by many attacks in recent decades, but cracked down on violent groups before the 2004 Olympic Games in Athens.

November 17, a left-wing group, killed 23 people in shootings and bombings between 1975 and 2002 before a botched bombing led police to capture key group members.

Last year, the US state department said it believed Revolutionary Struggle and November 17 could be linked.

Revolutionary Struggle has carried out at least six bombings since 2003, targeting police stations, government ministries, a bank and a courthouse.