At least 40 terrorists were killed in a US air strike Friday of an Islamic State base at Sabratha, west of the Libyan capital of Tripoli. American sources reported the presence at the base of the planners of two atrocities in Tunisia, the bombing of the National Bardo Museum in March 2015 in which 22 people died and the Soussa beach attack which killed 38 people, most of them British holidaymakers, last summer.