The Libyan Air Force is the branch of the Libyan Armed Forces responsible for aerial warfare. The Libyan Air Force personnel strength is estimated at 18 000 with and an inventory of 374 combat capable aircraft. There are 13 military airbases in Libya. After U.S. forces had left Libya in 1970 Wheelus Air Base a previous U.S. facility about seven miles (11 km) from Tripoli became a Libyan Air Force installation and was renamed Okba Ben Nafi Air Base.