Anti-aircraft fire and explosions have been heard in the Libyan capital Tripoli.
It is not clear who is being targeted in the attacks.
Meanwhile NATO has continued its air assault on Muammar Gaddaffi's forces in the eastern town of Brega.
Rebel forces are reportedly advancing on the oil town, as they push on from nearby Ajdabiya.
Al Jazeera Sue Turton filed this report from Brega.
