TRIPOLI - Two Italian construction workers abducted three weeks ago in Libya have been released after joint efforts by the two governments, Italian and Libyan officials said on Friday.

Details of their release were not immediately clear. The two men were kidnapped last month in Derna, east of Benghazi, where they had been working at a cement factory.

Italy's foreign ministry said on its website the two men were on their way back to Rome, without giving further details.

Derna is a hotbed of Islamist militant activity. But a local political activist said the men may have been snatched as part of a tribal dispute over jobs at the cement factory.

Nearly three years after the fall of Muammar Gaddafi, Libya's government is struggling to impose its authority on former rebels, armed groups and militants who once battled Gaddafi and now refuse to disarm.

Foreigners have been targeted for abductions by criminal gangs and for political purposes. A Korean trade mission official was snatched for a few days last month.

Gunmen in January kidnapped five Egyptian diplomats to demand the release of a Libyan militia commander who had been arrested in Egypt. They were released a day after and the militia leader returned to Tripoli.