American and coalition planes continued to enforce a no-fly zone over Libya while U.S. Tomahawk missile sorties continued. A U.S. F-15E fighter crashed during operations Monday, as Liz Sly, Craig Whitlock and William Branigin reported:

Both members of a U.S. fighter jet crew were rescued in eastern Libya after their F-15E Strike Eagle malfunctioned and crashed, the U.S. military said Tuesday, as fighting between rebels and loyalist Libyan forces continued around the strategic eastern town of Ajdabiya and in two towns in western Libya.

It was the first reported mishap to befall the U.S.-led coalition seeking to enforce a no-fly zone over Libya, and it came as friction intensified within the alliance over how far the campaign of airstrikes should go and who should take the lead.

China called for a cease-fire to avert “humanitarian disasters” after three nights of coalition strikes on Libyan military targets. The government of longtime leader Moammar Gaddafi claims the strikes have inflicted significant civilian casualties, a charge denied by U.S. officials.

The government has presented no evidence to reporters in Tripoli that the strikes have killed civilians. On Tuesday, officials took journalists to a Tripoli harbor to see a cluster of bombed warehouses that appeared to have contained military hardware.

The United States and its allies sought to maintain Arab support for the no-fly zone, which was criticized after the outset of airstikes. As Joby Warrick explained:

U.S. and European diplomats moved quickly Monday to rally wavering Arab support for military intervention in Libya after key Arab officials complained that Western airstrikes appeared to exceed the narrow mandate authorized by the United Nations.

The diplomatic outreach came as the first Arab warplanes to participate in the enforcement of the U.N.-backed no-fly zone — up to six French-built Mirage 2000 fighters from Qatar — began making their way toward Libya. Qatar is the only Arab country so far to firmly commit to contributing military firepower to the enforcement effort.

The Obama administration had stressed that Arab support was a precondition for foreign military action in Libya, but apparent waffling by some Arab leaders since the start of the bombing Saturday has raised concerns in Washington and other capitals. Secretary of State Hillary Rodham Clinton joined British and French counterparts over the past two days in phoning Arab leaders to shore up support after Libyan officials asserted that Western airstrikes had killed dozens of civilians.

After days of airstrikes cracks have appeared in the international coalition involved in the effort. As Greg Jaffe and Karen DeYoung reported:

The confusion over the mission, meanwhile, has spread beyond Libya. On Monday, NATO members bickered over whether what began as a relatively straightforward effort aimed at preventing Gaddafi from launching airstrikes against his people had turned into a more punitive action directed at his military forces, according to a European diplomat.

The disputes appear to have delayed U.S. efforts to turn the command of the operation over to NATO in the next few days. As of Monday evening, it remained unclear when responsibility would shift and who would assume it.

France, which has sought to portray itself as being in the vanguard of the operation, has raised concerns that Arab states will not participate in the operation if it is led by NATO. Turkey, which abstained from voting on the U.N. resolution, has said it sees no role for NATO.