TRIPOLI, Libya (AP) — Airstrikes hit a southeastern area of the Libyan capital early Sunday.

The sound of a jet plane, followed by an explosion at 1 a.m., sent up a huge cloud of white smoke, not far from the sprawling compound of Libyan leader Muammar Gaddafi at Bab al-Aziziyah

At least two more rumbling blasts could be heard in the east of the city and Libyan television confirmed that an “imperialist Crusader” bombardment had struck the district of Ain Zara, southeast of Tripoli.

A Libyan opposition group, Free Generation Movement, posted online that there were four explosions in the Ain Zara area and speculated the target could have been the External Security headquarters or facilities for storing weapons.

Under a U.N. mandate, NATO warplanes have been carrying out airstrikes on the Libyan government military targets.

Just 24 hours earlier there were a series of at least six explosions in the Bab al-Aziziyah area. NATO later reported a “command and control” facility had been hit.