Libya's forces say they have re-taken control of the port in the city of Sirte, following battles with Islamic State fighters, BBC reports.
Sirte is considered the most significant IS stronghold outside Iraq and Syria.
Earlier this week military jets shelled Islamic State-held positions in Sirte, while naval forces fired missiles into the port, officials said. The offensive is still ongoing.
The forces, loyal to the UN-backed unity government in Tripoli, began the fighting to put the city under their control in May.
Their spokesman, General Muhammad al-Ghusri, said senior IS leaders had fled into the desert to the south, but that many militants were still under siege in the city center.
The government said two soldiers were killed in the fight and eight were wounded.
Sirte was the hometown of ousted ruler Muammar Gadaffi.
The unity government was formed in Tripoli more than two months ago.
The US said the unity government should be allowed to provide itself with arms to oppose the Islamic State.
Secretary of State John Kerry has said this would be "the only way to generate the cohesion necessary" to defeat the militants.