ATHENS, Greece (AP) _ An leftist terrorist group claimed Saturday that it planted a bomb aimed at killing an American narcotics agent.

It also called for a shutdown of U.S. military bases in Greece.

Authorities said the bomb was defused Friday after it was discovered outside the suburban Athens home of George Carros, 50, a Drug Enforcement Agency officer attached to the U.S. Embassy.

In a statement sent to a left-wing Athens daily, the November 17 organization said ''commandos of our organization planted the powerful bomb.''

The statement called for the immediate closure of American military bases in Greece and described Carros as a ''representative of American imperialism.''

The group has claimed five attacks against Americans in the past 12 years.

Bomb disposal experts defused the nine-pound device. A security police spokesman, who spoke on condition of anonymity, said the remote-controlle d detonating system on the device had failed.

November 17, named after the day in 1973 when troops crushed a student uprising against the 1967-74 military dictatorship, first surfaced in 1975 when it claimed responsibility for killing Richard Welch, CIA station chief in Athens. None of the group's members has been arrested.

The last anti-American attack claimed by November 17 was an August car-bomb blast aimed at a a bus carrying American service personnel. Nine Americans and a Greek driver were slightly injured.

Carros had been posted in Greece for the past three years and was due to retire soon, according to American officials.