TRIPOLI, Libya -- A series of NATO strikes are targeting the Libyan capital.

Four explosions in quick succession were heard early Thursday, preceded by the sound of loud whooshing -- normally associated with cruise missiles.

After the strikes, the sound of speeding ambulances was heard by reporters staying in a Tripoli hotel.

It wasn't immediately clear what the strikes hit. Reporters are not allowed to leave their hotels without government minders.

The strikes came hours after Libyan leader Moammar Gadhafi made his first TV appearance since a NATO strike on his sprawling compound on April 30, in an attempt to quash rumors that he had been hit by the air strikes.

NATO strikes earlier this week hit an intelligence building and another structure used by parliamentarians.