Libyan rebels say they have entered the strategic oil port of Brega and are fighting street battles there with forces loyal to leader Moammar Gadhafi, the biggest offensive that eastern Libya has seen in weeks.
Reports from Brega Sunday described clashes in residential areas. Opposition leaders said at least 10 rebels have been killed in four days of fighting and 125 have been wounded. Casualty reports from the government side have been impossible to obtain.
Until Sunday, the rebel offensive to retake Brega had been limited mainly to mortar and rocket attacks from outside the city, as better-armed loyalists had slowed the rebel advance through the use of landmines and shelling. But Sunday's street fighting involved the use of machine guns at close range.
Brega is the site of a strategic oil terminal about 750 kilometers east of Tripoli. Rebels say re-taking the city would be a tipping point in the conflict on the eastern front.
The town has changed hands several times since the rebellion to oust Mr. Gadhafi began in February.
NATO warplanes bombed targets near the Libyan capital Sunday, a day after hitting pro-Gadhafi armored vehicles and rocket launchers near Brega.
The latest NATO air strikes shook the eastern outskirts of Tripoli before dawn. It was not immediately clear what targets were struck or whether there were any casualties. Mr. Gadhafi's forces have waged a five-month battle against rebels trying to end his 42-year-long autocratic rule.
Opposition forces who control most of eastern Libya and parts of the west are trying to advance on Tripoli from both fronts with the help of NATO air strikes on pro-government troops.
NATO reported hitting a range of Libyan military targets near Tripoli on Saturday, including a storage facility, three radar installations and a surface-to-air missile launcher.
Mr. Gadhafi has made a series of defiant speeches in the past week, vowing not to leave power as demanded by the rebels and Western allies.
Beginning Thursday, thousands of portrait-waving, pro-Gadhafi demonstrators have gathered amid a sea of green flags in the towns of Ajaylat, Zlitan and then Zawiya. The Libyan leader's words boomed from massive speakers during each rally.
The rebels won a diplomatic boost on Friday when representatives of 30 nations meeting in Istanbul declared the rebel Transitional National Council to be Libya's legitimate authority.