TRIPOLI - Libyan leader Muammar Gadhafi vowed not to surrender as NATO unleashed a series of daytime airstrikes on the capital Tripoli on Tuesday.

At least 15 loud explosions were heard, said a Xinhua correspondent. A fire broke out in Gadhafi's Bab al-Aziziya residential compound, an eyewitness told Xinhua.

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Intensive continuous bombardment, according to Libya's state TV, destroyed buildings and infrastructure in the area of Bab al-Aziziya.

Smoke could still be seen billowing from a nearby military base although Libyan civil defense teams managed to douse the fire, a Xinhua correspondent said.

In a nine-minute audio message late Tuesday, Gadhafi said that he was close to the bombing but would neither kneel nor surrender.

"We have only one choice - to stay in our country to the end, dead or alive," he said, adding that the Libyan people will march across the country to cleanse it from "armed gangs," referring to opposition forces controlling eastern Libya.

The world's major powers, Britain, the United States and France, have launched airstrikes against Gadhafi's forces since March 19 after the UN Security Council passed a resolution to impose a no-fly zone over Libya and authorize "all necessary measures" to protect civilians in Libya.

NATO took over full command of military operations against Libya from the United States on March 31.