TRIPOLI - Loud explosions and heavy anti-aircraft gunfire were heard in the Libyan capital city of Tripoli at around 9:00 pm local time (1900 GMT) on Monday as the third round of Western-led airstrikes started.

Anti-aircraft artilleries were fired into the sky from the north and east parts of the city, while the anti-aircraft fire was also heard in south part of the city.

A French Air Force Mirage 2000 fighter jet makes preparations at the Solenzara military air base before a mission over Libya March 21, 2011. [Photo/Agencies]

One military barrack 30 km west to Tripoli was bombed, a local source told Xinhua reporters Monday.

A navy base near the broadcasting and TV station in the capital was targeted in the military strikes, which also hit an oil pipeline in Shaab, a port city east of Tripoli.

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After the explosion, Libyan government spokesman Mussa Ibrahim held an emergency press conference to strongly protest the bombing.

He said Western countries has launched three consecutive days of air strikes after Libyan armed forces announced a comprehensive cease-fire and stopped all military actions. The majority of Libya's civil airports and seaports were destroyed during the airstrikes.

Libyan state TV said many civilians were killed and wounded in the new round of attacks.

Similar explosions rocked the capital on Sunday, with coalition officials on Monday saying an administrative building of the residence compound of Libyan leader Muammar Gaddafi was destroyed by a missile.

Footage of the Libyan state TV showed that a building near the tent where Gaddafi usually receives guests was severely damaged.

"It was a barbaric bombing" and could have hit hundreds of civilians who gathered near the destroyed building in support of the Libyan leader, said Mussa, who declined to say whether Gaddafi was still inside the compound.

He said the airstrikes have caused heavy civilian casualties. At least 64 Libyans had been killed and 150 others wounded by the missiles and bombs rained upon Libya over the weekend. But the intervening forces denied targeting civilians.

Government forces of Libya pulled back 100 km from the main opposition stronghold of Benghazi on Monday after a weekend of air attacks.

The forces retreated to the strategic town of Ajdabiya, south of Benghazi, after the airstrikes destroyed much of their armor and  seriously degraded the North African country's air defense systems.

Dubbing the attacks "a crusader war" against the Libyan people, Gaddafi said Sunday that the airstrikes were "terrorist means" and he vowed a "long war."