heather: fox news alert. tripoli under attack. we re getting reports that air-raid sirens and explosions are being heard across the capital and on gadhafi s hometown. steve is streaming live. what is the very latest? reporter: in the past 45 minutes we ve heard eight loud incoming explosions. this is the ninth night of attack on tripoli. we re not sure what the exact target is but they are landing in the eastern part of the city. as far as the battlefield on the ground, it s changed over the last 24 hours. rebels making an extremely rapid advance moving quickly to the west. they ve retaken four cities. it s not really as much due to their fighting prowess. they are attacking tanks and supply trucks brigham anything