The siege of Misrata continued in full force Tuesday as Muammar Gaddafi’s forces pounded the city with tank and artillery fire. Meanwhile, rebels were halted in their attempt to regain control of Ajdabiya, failing to take advantage of a third day of coalition airstrikes.

Residents report a desperate situation in Misrata, where civilian casualties, including children, are mounting. The city center is occupied by government tanks and snipers have joined the attack, according to one citizen who spoke to Reuters.

Meanwhile, a U.S. F-15E warplane crashed from apparent mechanical failure, the first allied jet to be lost in the campaign. Both crewmen were rescued. Air units from Qatar and the United Arab Emirates are expected to join the fight this weekend.

The U.S. has said it will relinquish its leadership role in the campaign in a matter of days, but it is unclear who will take over. France and Turkey have objected to NATO assuming overall command of the operation, with the Turkish Prime Minister insisting the campaign should fall under U.N. control.

At the U.N., Russia called for a meeting Thursday to determine if the intervention has gone beyond its mandate. Brazil and China have called for a ceasefire.