Masked gunmen attack riot police in Athens

ATHENS, Greece (CNN) -- Gunmen fired automatic weapons at Greek riot police in Athens Monday, seriously injuring a policeman in an attack police said looked like the work of one of the country's leading Marxist militant groups.

Police issued statements saying the attack bore the hallmarks of Revolutionary Struggle, a Marxist group that claimed responsibility for an attack on the U.S. Embassy in Greece in 2007. No one has claimed responsibility for Monday's attack, which followed weeks of violent protests sparked by the fatal police shooting of a teenager last month.

But police said one gun that was fired Monday was used in an April 2007 attack on a police station. Revolutionary Struggle claimed responsibility for that attack.

A second gun from Monday's incident was fired in a December 23 attack on a police riot van, police said. That attack was claimed by a previously unknown group calling itself Popular Action. No one was injured in that incident, which police considered a warning, rather than an attempt to kill.

Police based their analysis on ballistics tests. They do not have the guns in custody.

At least two masked gunmen sprayed more than 20 shots at the riot unit Monday, hitting a 21-year-old officer in the chest and groin while he was guarding the Culture Ministry in central Athens, authorities said. The wounded policeman, identified as Diamandis Matzounis, was in critical condition after being rushed to a hospital, health ministry officials said.

None of the other 20 police on board the bus stationed near the state building were injured in the pre-dawn attack.

Authorities said they had cordoned off the area around the site of the attack to collect evidence. At least 72 people were detained during the initial search for suspects.

There was no immediate claim of responsibility for the attack, which came a day before the one-month anniversary of the fatal shooting of Alexis Grigoropoulos, 15, by a police officer in Athens.

Prime Minister Kostas Karamanlis visited the wounded officer in Erythros Stavros Hospital on Monday.

"The police are hard working co-citizens. They are public servants, assigned with the task to work for everyone. The bullets fired against them hit the Republic and society as a whole," Karamanlis said in a statement released after his visit.

"Those who attacked Diamandis Matzounis targeted democracy and order," Interior Minister Prokopis Pavlopoulos said after visiting the wounded officer. "They will soon realize that democracy is strong and our society is safeguarded."

The attack came two weeks after gunmen using an automatic rifle fired on a riot police van in Athens. No one was injured in that attack, but authorities were placed on high alert.

"This attack was unfortunately something that we had been expecting," said Stavros Mavroidakos, a representative of Greece's National Elite Guard, a specially trained police unit.