The latest strikes on Gaddafi's stronghold came just hours after the International Criminal Court's chief prosecutor sought arrest warrants for the Libyan leader, his son and the country'' intelligence chief for authorising the killing of civilians in a crackdown on anti-government rebels.
Gaddafi's government denied the allegations.
The call for the inquest was the first such action in the Netherlands-based court linked to the Arab uprisings. It opened another potential front against Gaddafi's regime even as the autocratic leader stands firm against widening NATO airstrikes and rebels with growing international backing.
A Libyan government spokesman appealed for a ceasefire and said authorities were likely to release four foreign reporters held in a Tripoli after they face trial in an administrative court, expected later today.
NATO has stepped up strikes on Tripoli in an apparent attempt to weaken Gaddafi's chief stronghold and potentially target the leader himself. One of the buildings hit early today was used by the Interior Ministry which is responsible for internal security.
Government escorts took reporters from their hotel to the site of the overnight airstrikes. Smoke and flames engulfed the top floors of the Interior Ministry building as dozens of young men, many of them armed with assault rifles, milled outside the shuttered gate early today.
Some of the men carried a life-sized portrait of Gadhafi, danced before the burning building and chanted: "The revolution will continue!" Nearby, black smoke poured out of a complex that officials said included offices used by authorities overseeing corruption cases. Soldiers collected half-burnt papers strewn amid the smashed glass and twisted metal as fire fighters sprayed water on the flames.
Moussa Ibrahim, the Libyan spokesman. suggested the ministry was targeted because it contained files on rebel leaders in Benghazi, the de-facto capital of the eastern half of the country, which is under opposition control.
"If they (NATO) are really interested in protecting civilians ... then we call upon them to stop and start talking to us," Ibrahim said.