Iran must pay $2.65 billion to the families of the 241 US service members killed in the 1983 bombing of the US Marine barracks in Beirut, a federal judge declared Friday in a ruling that left survivors and families shedding tears of joy.

US District Judge Royce C Lamberth described his ruling as the largest-ever such judgment by an American court against another country. "These individuals, whose hearts and souls were forever broken, waited patiently for nearly a quarter century for justice to be done," he said.

Iran has been blamed for supporting the militant group Hezbollah, which carried out the suicide bombing in Beirut. It was the worst terrorist act against US targets until the Sept. 11, 2001 attacks.

Hundreds of people crowded into a federal courtroom to hear Friday's ruling. Parents have grown old since their children were killed. Siblings have grown into middle-age. Children have married and started families of their own.

Weeping spectators stood and erupted in applause and hugs as Lamberth left the bench.

The ruling allows nearly 1,000 family members and a handful of survivors to try to collect Iranian assets from various sources around the world. Finding and seizing that money will be difficult, however, and the families are backing a law in Congress that would make it easier for terrorism victims and their families to do so.

Families were encouraged by Libya's decision to ultimately accept responsibility for the 1988 bombing of a Pan Am flight over Scotland. The country, once a pariah by Washington's view, agreed to compensate the families of the 270 victims. Part of the $2.7 billion has been paid. A final $2 million instalment to each family is outstanding.