A Return to Terror?

The anti-terrorist brigade was conducting inquiries, with the main suspect being extreme-left group Revolutionary Struggle.

The policeman on duty said three men, on foot, fired automatic weapons at the sentry boxes and outside walls of the police station, and threw a grenade which failed to explode. Police closed off the street while sappers examined the grenade.

Revolutionary Struggle had on January 15 threatened fresh attacks on police after two hits in which a young policeman was injured, and called for an armed uprising to overthrow capitalism.

In an eight-page manifesto published in Greek weekly Pontiki, the elusive group considered Greece's most dangerous extremist organization said it fired on police to avenge the fatal shooting of a teenager by an officer in December.

"We respond to bullets with bullets ... from now on, we can only defend with arms the value of human life of the poor, the outcasts, the damned," it said.

The death of 15-year-old Alexander Grigoropoulos on December 6 sparked a wave of violence unseen in Greece for decades. Young protesters battled police across the country and hundreds of stores were vandalized, which the group said was "a good message for what is to follow."

"Society is a boiling cauldron. The cop's bullet sparked a long-awaited social conflagration which heralds even wider uprisings.

"For the first time in many decades, a path opens ... to overthrow the political and economic system," the manifesto said.

Best known for firing an anti-tank rocket at the US embassy in Athens in 2007, Revolutionary Struggle said the attacks on police also came in reprisal for a long tradition of unpunished brutality to protesters and migrants.

Second alleged attack by Revolutionary Struggle

The group said two of its members on January 5 ambushed a police patrol behind the Greek culture ministry and seriously injured policeman Diamantis Matzounis, 21.

A fortnight earlier, Revolutionary Struggle said it had fired shots at a riot police van that missed the 23 officers on board.

The group first appeared in 2003 and has claimed responsibility for several attacks that have left three people slightly injured.

Greece and the United States have offered a combined two-million-dollar reward for information leading to the capture of the group, which figures on the European Union's list of terrorist organizations.

Revolutionary Struggle is considered the successor of November 17, the country's deadliest extremist organization that killed 23 people between 1975 and 2000 before its demise in 2002.