UN aid chief Valerie Amos has called for a pause in hostilities in Libya to help ease the humanitarian crisis. Baroness Amos told the UN Security Council that Misrata, the only rebel-held city in western Libya, was in a dire state and short of food and water. Three-quarters of a million people have fled Libya since an uprising began against Col Muammar Gaddafi's rule. Meanwhile rebels in Misrata say they have pushed government troops back from its outskirts. Misrata, the only city in western Libya under rebel control, has been under siege from forces loyal to Col Gaddafi for two months. In Tripoli, blasts were heard overnight in what reportedly were Nato strikes. Eyewitnesses spoke of at least five air strikes which are believed to have targeted Col Gaddafi's compound and other government buildings. The Libyan government has so far made no public comments about the explosions. Last week, a boat carrying 600 refugees broke up shortly after leaving Tripoli port. It is not clear how many people died, but eyewitnesses reported seeing bodies, wreckage and survivors swimming back to shore. The UNHCR has called on all ships using the Mediterranean to be prepared to offer assistance to the often unseaworthy vessels carrying migrants from Libya to Europe. At least three other boats have been reported missing in the Mediterranean. 'Widespread shortages' Baroness Amos said the disruption caused by a combination of the conflict and sanctions was paralysing the country. She called on the Security Council to ensure that all parties respected international law and she said the use of cluster bombs, sea and land mines, as well as aerial bombing showed a callous disregard for civilians. The conflict and disrupted supply lines had delayed the arrival of commercial goods, she said. "Widespread shortages are paralysing the country in ways which will impact gravely on the general population in the months ahead, particularly for the poorest and the most vulnerable," she added. There was only enough food left for a few months, she said. She renewed calls for money, saying an appeal for $144m (£88m) had only been half met, and more than that would be needed. A Red Cross ship successfully docked in Misrata on Monday, bringing medical equipment, baby food and spare parts for electrical and water systems. The port has become a lifeline for the city, allowing refugees to leave and supplies to be brought in, but has come under repeated attack from pro-Gaddafi forces. Medical sources say at least 300 people have been killed by the weeks of fighting in Misrata. 'Keep going' The rebels say Misrata remains surrounded, but that they have advanced about 30km (18 miles) to the west. An AFP correspondent in Misrata said the rebels were now in control of a stretch of coastline heading towards the capital. A rebel spokesman, Mohammed, told the BBC: "We've pushed Gaddafi away from Misrata." He said the morale of the rebels was high, and that "they want to keep going". Source: BBC