An urban guerrilla group called November 17 is suspected of the car-bomb murder of the military attache at the American Embassy here, Greek police said Tuesday.
Navy Capt. William Nordeen, 51, was blown out of his armor-plated car and killed earlier in the day when a car bomb was detonated as he drove by on his way to work.
The explosives, packed in a Toyota car parked about 300 feet from Nordeen's home, were apparently detonated by remote control, police bomb experts said.
The blast threw Nordeen 45 feet into a neighboring garden, shattered surrounding windows, cut overhead power lines and demolished the two cars.
A police explosives expert who refused to be identified said the bombing was "perfectly planned and very well executed. . . . They thought of every detail."
The expert said bags of cement were piled against one side of the booby-trapped vehicle so the explosion's full force would be directed toward Nordeen's car.
At the time, Nordeen's wife and 12-year-old daughter were believed to be at home in the wealthy suburb of Kefalari, where many American and foreign diplomats live.
In Washington, the White House condemned the incident as a "senseless act of brutality."
Spokesman Marlin Fitzwater said no group had yet claimed responsibility and the United States had no clues as to who planted the bomb.
"We condemn this senseless act of brutality," Fitzwater said. "We will work with Greek authorities to bring the murderers to justice."
American military personnel have been a favorite target of November 17, an extreme left-wing urban guerrilla group.
Police sources said they believe that November 17 was the only group capable of carrying out such a sophisticated attack. It assassinated U.S. naval attache George Tsantes in November, 1983.
November 17 started its campaign of political murders and bombings in 1975, when it shot and killed CIA station chief Richard Welch.
The group takes its name from the date of a student uprising at the Athens Polytechnic University in 1973 against the military junta that then ruled Greece.
Nordeen, who was from Centuria, Wis., was due to retire in August after 30 years in the Navy, said his sister, Carla Anderson.
In Centuria, Nordeen's mother, Edna Capello, said: "I just can't believe it. I'm just stunned. . . . His poor wife and child."
The Socialist government of Prime Minister Andreas Papandreou issued a statement expressing "its abhorrence over Nordeen's murder" and saying its "position on confronting and combatting terrorism is well-known and categorical."
The killing was the latest in a series of assassinations and bomb attacks by various groups in and around Athens this year.
November 17 claimed responsibility for shooting and killing Greek industrialist Alexandros Athanassiades in March and planting a series of bombs that wrecked the cars of Turkish diplomats when Foreign Minister Mesut Yilmaz visited Greece in May.
A previously unknown left-wing group, the Revolutionary Organization Popular Struggle, claimed responsibility for a bomb blast at a bar popular with U.S. servicemen in March. Fourteen people, including four Americans, were injured.