A Libyan court has jailed 24 foreigners accused of being mercenaries for Muammar Gaddafi's regime during last year's conflict.

The men from Ukraine, Russia and Belarus were found guilty of repairing surface-to-air-missile batteries.

Sentences range from life imprisonment for the man identified as the group's co-ordinator, to 10 years of hard labour for the others.

The men deny the charges and insist they were just oil workers in Libya.

The judgment, the first of its kind, was handed down following several hearings in recent months.

The men were captured by rebel fighters last August in the Tripoli suburb of Girgaresh, shortly after Col Gaddafi's regime was toppled.

They were reportedly detained along with a number of Africans and Libyans also accused of being mercenaries.

Ukraine has rejected the judgment, saying the men were innocent.

Ukrainian ambassador Mykola Nahornyi told Reuters news agency they had initially come to Libya to work for an oil company, but were forced to stay on after conflict broke out to help build anti-aircraft material.

"The court's verdict was inconsistent with the laws of the countries of the citizens who were tried," he said. "We will continue our efforts to appeal and our final goal is to bring these citizens home."

The former Gaddafi regime maintained close ties with Europe's Eastern Bloc for decades.

Russia and the Ukraine were among the last nations to recognise Libya's new transitional authorities.