A column of gray smoke could be seen rising from the area around Gadhafi's Bab al-Aziziya compound shortly before dawn Tuesday. The concussion from the blast was felt at a hotel where journalists stay in the capital.

It was not clear what was targeted, and Libyan officials didn't immediately comment.

East of the capital, alliance aircraft have begun dropping leaflets warning government troops to abandon their posts outside Zlitan, which lies just west of the rebel-held port city of Misrata.
Rebel forces have been advancing along the Mediterranean coast toward Zlitan, but say they have been instructed by NATO to withdraw ahead of expected bombing runs to old front lines in Dafniya.