In the initial days of the war, an Iranian F-5 fighter jet bombed the U.S. base Camp Buehring in Kuwait, despite the base having air defenses, a rare breach that marked the first time an enemy fixed-wing aircraft has struck an American military base in years, according to two of the U.S. officials.

The three U.S. officials familiar with the damage to U.S. bases in the Middle East described it as extensive. The headquarters building for the U.S. Navy in Bahrain, the nerve center for the Navy’s operations in the region, sustained serious damage, the officials said. They said other parts of the base in Bahrain also suffered significant damage that is likely repairable.

Multiple hangars and warehouses at Ali Al Salem Air Base in Kuwait also were struck, according to the American Enterprise Institute’s unofficial assessment that was reviewed by NBC News. The assessment also shows a munitions storage facility at a military base in Erbil in northern Iraq was damaged and a runway at the sprawling Al-Udeid Air Base in Qatar was destroyed.