The Iranian government was accused Monday of ordering the 1983 terrorist bombing that ripped through a U.S. Marine barracks in Beirut, Lebanon, and killed 241 Marines.

The explosion was part of a larger plot to drive all Americans out of Lebanon, said a lawyer representing 153 families suing Iran for more than $2 billion in damages.

The suicide truck bombing was blamed on the militant Muslim group Hezbollah, which was supported by Iran. The plaintiffs' Attorney Thomas Fortune Fay said evidence showed the Iranian government acted alone, and that its late supreme cleric, Ayatollah Ruhollah Khomeini, and other top leaders ordered, authorized and executed the bombing.

"The political purpose of the attack was to remove the United States as a factor from Lebanon," Fay said in his opening statement to U.S. District Court Judge Royce C. Lamberth, who is hearing the case without a jury.

Representatives of neither the Iranian nor the U.S. government responded to the plaintiffs' arguments. In the absence of diplomatic relations between Iran and the United States, oversees Iranian property and other holdings in the country and Pakistan is in charge of other Iranian interests.

A truck carrying more than 2,000 pounds of explosives sped past a sentry post and exploded outside the Beirut barracks in the early hours of Oct. 23, 1983, as many servicemen slept.

Retired Adm. James Lyons, who was deputy chief of naval operations in 1983, testified about an intercepted message from the Iranian ambassador to Syria, who told Iranian officials "to take spectacular action against the U.S. Marines" in Beirut.

"If there was ever a 24-karat gold document, this was it," Lyons said.

Robert Baer, a former CIA agent who spent more than two decades collecting "outstanding intelligence" on the attack, said Iran planned to stamp out the U.S. presence in Lebanon by killing American diplomats and servicemen and kidnapping its civilians. He dismissed any suggestions that Hezbollah played a role in the attacks.

"The terrorist operations were funded directly by Iran and didn't even go through Hezbollah," he said in video testimony.

The Marines killed and wounded in the attack were part of a multinational peacekeeping mission. President Reagan ordered the troops withdrawn from Lebanon a few months after the bombing, during which attackers hit other U.S. and allied targets.

The lawsuit against Iran was filed under a 1996 U.S. law that allows Americans to sue nations that the State Department considers sponsors of terrorism for damages suffered in terrorist acts.

In an opinion last year, Lamberth said the law could be applied to American servicemen under certain circumstances.

The case was expected to last about two days.

Deborah Peterson, lead plaintiff in the case, lost a brother in the Beirut explosion.

She said the lawsuit is intended to hold Iran responsible for its actions and "possibly deter terrorism in the future." She said she hopes to collect compensation but mainly wants "Iran to hurt the way they've made us hurt."

Steven Perles, another family attorney, said any judgment the families win could be awarded from Iranian assets frozen in U.S. accounts and businesses. He said experts estimate that Iran could have $4 billion to $6 billion in such investments.