Benghazi: Libyan rebels battling Muammar Gaddafi's troops along the country's Mediterranean coast have claimed they captured part of a strategic port city that has repeatedly changed hands in the 6-month-old civil war.

Rebel spokesman Mohammed al-Zwawi said he was with the fighters when they gained control on Thursday of a residential unit in Brega.

Brega is a wide strip of desert made up of two residential units about 10 kilometres apart, followed by the oil refineries near the port on the Mediterranean Sea.

"We have taken the first residential unit and we are fighting in the second one now," al-Zwawi told a newspaper on Friday.

His claim could not be immediately verified and officials in the Libyan capital Tripoli made no comment on it.

Eleven rebels died in the clashes and 40 were wounded, rebel leader Mohammed Idris said late on Thursday.

Brega, about 200 kilometres southwest of the de-facto rebel capital of Benghazi, fell under rebel control briefly in March, but was recaptured by Gaddafi's forces shortly afterward. The fighting around the city has gone back and forth since then, with the rebels not managing to keep their ground.

Whoever controls Brega's strategic oil terminal, which is also Libya's second-largest hydrocarbon complex, is in charge of the country's main oil fields.

A video released on Youtube showed a rebel fighter performing the call to prayer from the top of a mosque's minaret in Brega, as the rebel tricolour flag fluttered beside him.