TRIPOLI, Libya — The Libyan foreign minister said today that Libya is declaring a cease fire and stopping military operations.

But Moammar Gadhafi’s forces earlier today bombarded the last rebel-held western city as the international community raced to stop him after the U.N. authorized “all necessary measures” to protect the Libyan people, including airstrikes.

The attack on Misrata, Libya’s third-largest city, comes as the rebels were on the defensive in their eastern stronghold after Gadhafi vowed to launch a final assault and crush the nearly 5-week-old rebellion against him.

The opposition expressed hope the U.N. resolution, which was passed late Thursday after weeks of deliberation, would help turn the tide in their favor after days of fierce fighting.

The U.N. Security Council resolution sets the stage for airstrikes, a no-fly zone and other military measures short of a ground invasion.

Britain announced that it would send fighter jets and France was making plans to deploy planes, but as of this morning the U.S. had yet to announce what its role would be. NATO also was holding an emergency meeting.