Go to LBO front page at www.lbo.lk for updates on this developing story. Officials said a suspected Tamil Tiger aircraft intrusion prompted the blackout.
Tracer fire was seen was in several locations in Colombo.
Earlier this week authorities blacked out Colombo and anti-aircraft fire was directed at the sky over Katunayake international airport on a suspected flying Tiger intrusion.
Some aircraft were diverted out of the international airport, but flights resumed within a short time.