There are reports of explosions and gunfire in the Libyan city of Misrata, despite an announcement that the Libyan army had halted operations there. Deputy Foreign Minister Khaled Kaim said the army had stopped fighting to give local tribal leaders an opportunity to negotiate with rebels. But he said government troops had not withdrawn from the besieged port city. Rebels dismissed previous reports of an army retreat. Saturday was one of the bloodiest days yet in Misrata. Misrata - Libya's third largest city - is the rebels' main stronghold in the west of the country. Human rights groups say more than 1,000 people have been killed in weeks of fighting in there, as rebels have struggled to fend off attacks by forces loyal to Libyan leader Col Muammar Gaddafi. 'Military option' Early on Sunday, Mr Kaim said armed forces had not withdrawn from Misrata, but "ceased operations" because tribal leaders "decided to... do something to bring back ordinary life to Misrata". "The other option which is still available from the heads of the tribes is the military intervention to liberate Misrata," he said. However, correspondents reported bursts of automatic weapons fire and rocket explosions in the city. A Misrata resident told the BBC that pro-Gaddafi had been firing rockets on residential areas overnight. The account could not immediately be verified. On Saturday Mr Kaim said tribes around Misrata had given the army an ultimatum that if it couldn't defeat rebels in Misrata, their fighters would. He said tribal leaders were angry that fighting had brought life and trade in the western city to a standstill. But the loyalties of different tribes are not certain, the BBC's Peter Biles reports from the rebel-held city of Benghazi. While some groups may be supportive of Colonel Gaddafi, others, including the non-Arab tribes of Misrata, rebels say others have been fighting on their side. There were conflicting reports about whether forces loyal to Col Gaddafi had pulled back from the centre of the city. Tripoli hit Rebel leaders in Benghazi have said Libyan Col Gaddafi is "playing games" and would not allow his forces to leave Misrata. On Saturday, at least 24 people were killed and 100 wounded during fighting in the western city. Meanwhile, Nato aircraft have carried out more air strikes on targets around the capital Tripoli and other cities, Libyan state news agency Jana reported. Foreign journalists based in Tripoli reported hearing three large explosions late on Saturday as jets flew overhead. On Saturday, the US confirmed the first strike by one of its unmanned drone aircraft over Libya, destroying a government rocket launcher near Misrata. In a statement, Nato said it had carried out more than 3,000 sorties since assuming control of the UN-backed mission late last month. "We have struck a broad range of targets across the country - tanks and rocket launchers, armoured vehicles and ammunition stores, command and control sites," it added in a statement. The popular revolt against Col Gaddafi - inspired by similar uprisings in Egypt and Tunisia - began in February and a UN mandate later sanctioned air strikes against Libyan state forces to protect civilians. Source: BBC