TRIPOLI, Libya - Several explosions and bursts of anti-aircraft fire were reported in the Libyan capital Sunday.
There were at least nine loud explosions in Tripoli after nightfall, and anti-aircraft fire was heard.
An Associated Press reporter in the capital said international forces were heavily bombarding the city that is Qaddafi's main support base.
Libyan State Television issued a news flash that civilian and military areas had been hit "by the crusader, colonialist aggressors."
State TV also reported that international airstrikes were targeting Muammar Qaddafi's hometown and stronghold of Sirte for the first time.
Foreign journalists in the city reported loud explosions and warplanes flying overheard.
Sirte is strategically located about halfway between the rebel-held east and the Qaddafi-controlled west along a key coastal highway. Rebels were advancing rapidly west on the highway Sunday toward Sirte after international airstrikes eased their way.
Earlier today in Brussels, NATO announced it would assume command of all aerial operations - including ground attacks - in Libya, taking over from the U.S.-led force that has been conducting airstrikes against Qaddafi's forces.
Ambassadors on Sunday approved a plan to expand the previously-agreed mission to enforce the U.N. arms embargo and no-fly zone, by agreeing to protect civilians from attack by Qaddafi's ground forces, a diplomat said
The diplomat (who asked not to be identified because he was not authorized to speak to the media) said the transfer of authority may take several days.
In making the announcement, NATO Secretary General Anders Fogh Rasmussen said, "Our goal is to protect civilians and civilian-populated areas under threat of attack from the Qaddafi regime. NATO will implement all aspects of the UN Resolution. Nothing more, nothing less."
Today's decision goes beyond enforcement of the arms embargo and no-fly zone, Rasmussen said: "We will be acting in close coordination with our international and regional partners to protect the people of Libya.
"We have directed NATO's top operational Commander to begin executing this operation with immediate effect," Rasmussen said.
Earlier Sunday, Libyan rebels seized back the oil refinery of Ras Lanouf, after taking control of Brega, another oil complex, on eastern Libya's coast yesterday, as they continued their push west toward Tripoli.
The Qaddafi regime on Saturday acknowledged the airstrikes had forced its troops to retreat and accused international forces of choosing sides.
"This is the objective of the coalition now, it is not to protect civilians because now they are directly fighting against the armed forces," Khaled Kaim, the deputy foreign minister, said in the capital, Tripoli. "They are trying to push the country to the brink of a civil war."