People look at a U.S Air Force F-15E fighter jet after it crashed near the eastern city of Benghazi. (Suhaib Salem/Reuters)

An American F-15 fighter jet crashed Monday night in Libya. Its crew members are safe, according to the U.S. military. As airstrikes continue in Libya and NATO disagrees over the international mission, my colleague Sudarsan Raghavan writes:

Even as allied strikes hammer Gaddafi’s air defenses, his ground forces have dug in within heavily populated urban areas such as Ajdabiya, and on Monday they gained ground in the western city of Misurata.

U.S. officials say the three-day-old international military intervention is intended to protect Libyan civilians, not provide support to Libya’s opposition. But Monday’s setbacks for the rebels revealed the degree to which the disorganized and ill-equipped force is depending on allied airstrikes to end Gaddafi’s 41-year rule. It also raised questions, so far unresolved, about how far coalition members are prepared to go to help Libya’s opposition.

Meanwhile, in Yemeni President Ali Abdullah Saleh is quickly losing support among top tribal leaders and diplomats. The Post’s Hakim Almasmari and William Branigin write:

Maj. Gen. Ali Mohsen al-Ahmar, a powerful commander and longtime ally, announced his “support for the peaceful revolution” and condemned the repression of protesters. Two other prominent commanders, Brig. Gens. Mohammed Ali Mohsen and Hameed al-Qusaibi, and a score of other senior officers also sided with the opposition.