A US air strike targeting an Islamic State training camp in Libya "likely" killed an IS operative linked to two major jihadist attacks in Tunisia last year, a US defense official said Friday.

"The US conducted an air strike early this morning (Libya time) against an ISIL training camp near Sabratha, Libya, that likely killed ISIL operative Noureddine Chouchane," the official said, using an alternative acronym for the IS group.