In the latest development in Libya, strong explosions were heard in the Libyan capital of Tripoli Sunday night, with smoke rising near Libyan leader Muammar Gaddafi's residence.

The latest blasts happened after a Libyan military spokesman announced earlier Sunday that a ceasefire would start from 9:00 p.m. local time.

Heavy anti-aircraft fire lit up the night sky over Tripoli. The US claimed initial success two days into an assault on Libya that included some of the heaviest firepower in the American arsenal.

A second wave of coalition attacks, mainly from American fighters and bombers, targeted Libyan ground forces and air defenses, following an opening barrage Saturday of sea-launched Tomahawk cruise missiles.

Pentagon officials say the attacks do not fully eliminate the threat from Libyan air defenses, and they are studying the extent of damage done and the need for further attacks.

US missiles and warplanes were clearly in the lead Saturday and Sunday, but U.S. officials say the plan remains for the US to step back once the threat from the Libyan military is reduced.

The Pentagon reports no aircraft lost in coalition attacks so far on Libyan air defenses and ground forces and says it's not aware of any civilian casualties in the attacks.

The Pentagon added the United States does not have Libyan leader Muammar Gaddafi on its target list'.

Although the mission was predicated on Arab support, there was no reported Arab participation in the military strikes. The US military says Qatar will be "in the fight" in the next day or two after moving unspecified military aircraft to within striking range.

In response to Libyan military's claim that all army units across the country have been told to observe a ceasefire, the Pentagon said it questions all statements from Gaddafi's government.

The Libyan government had already announced a unilateral ceasefire last week, but Western powers then accused Gaddafi of breaking the truce -- a charge denied by the government.