Despite four nights of missile and airstrikes, Muammar Gaddafi's forces pressed ahead with their assault on key towns of Misruta, Ajdabiya and Zintan. His tanks and heavy artillery laid a siege on the embattled Misruta, the sole city held by the rebels in western Libya, and heavy shelling by his forces left more than 50 people, including children dead. According to reports, intense fighting also raged for the town of Zintan where outgunned rebel forces were repeatedly thrown back by government troops. Loud explosions continued to rock the capital for the fourth night and flares from the firing of anti-aircraft guns lit the sky. Libyan leader declared on Wednesday that they will not surrender. He said they will prefer to die like martyrs. Gaddafi said this in a live television broadcast, making his first public appearance since the allied strikes against his country. BBC said that divisions were appearing among the rebels, with some pressing for pushing on to Tripoli, while others wanted to take Ajdabiya and consolidate their hold in the East, hoping Libyan in other cities will rise up and liberate themselves. The US has slapped sanctions on 14 companies controlled by Libya's state oil company. The move has cut off a key source of funds for the Muammar Gaddafi's regime. Director of the Treasury Department's Office of Foreign Assets Control Adam J Szubin said, the Libyan National Oil Corporation has been a primary funding source for the Gaddafi regime. He said, Consistent with UN Security Council Resolution 1973, all governments should block the National Oil Corporation's assets and ensure that Gaddafi cannot use this network of companies to support his activities.