BBC News with Nick Kelly
A series of massive explosions have shaken the Libyan capital Tripoli in what appears to be a major Nato air strike. Columns of smoke rose above the neighbourhood where Colonel Gaddafi's residential compound is located, as Andrew North reports from Tripoli.
These appear to be the largest Nato strikes on Tripoli so far, and they are still going on. They began around 1:00 am local time with three
thunderous
explosions from the direction of Colonel Gaddafi's compound, followed by a series of even larger blasts much closer to our hotel. Plumes of smoke are now coming from the area around the Libyan leader's compound. The whole building shook, with the force of each explosion. There were flashes of bright light just before each blast, and aircraft were then heard overhead. Libyan anti-aircraft guns have been
opening up
into the night sky, firing streams of tracer around.
Earlier, it emerged that France and Britain are to deploy attack helicopters against Libyan to try to break the military
stalemate
.
France has dispatched 12 helicopters on an aircraft carrier; Britain is expected to send Apache helicopters based on the country's largest warship. Our defence correspondent Caroline Wyatt reports.
The move to use attack helicopters in the campaign marks a
significant
escalation of the conflict in Libya and a stepping-up of Nato's pressure on Colonel Gaddafi and his forces after weeks of near stalemate. Most of Colonel Gaddafi's troops have shed their uniforms and are using civilian vehicles and hiding armour near civilian buildings, including hospitals and schools, making targeting from fast jets high up in the skies much harder. However, there are dangers involved in the use of helicopters. They are more