WASHINGTON • The United States has broadened its fight against the Islamic State in Iraq and Syria (ISIS), targeting the group's senior leader in Libya on Friday night, the Pentagon said.

The air strike against the ISIS commander took place shortly after the attacks in Paris began, but had been in the works for several days and was not related to the events in France, US officials said.

Western officials have been warning for months about a growing threat from militants in Libya aligned with ISIS.

The strike in the town of Derna in eastern Libya was aimed at Abu Nabil. He is an Iraqi national who led Al-Qaeda operations in western Iraq from 2004 till 2010. He later moved to eastern Libya to lead ISIS operations there, the officials said.

The Pentagon said it believed the strike had killed Abu Nabil, though it would take a few days to confirm that. The strike, which was carried out by F-15E attack planes based in Britain and was first reported by The Daily Beast, is the first time the US has targeted a senior ISIS operative outside of Iraq or Syria.

"Nabil's death will degrade ISIL's ability to meet the group's objectives in Libya, including recruiting new ISIL members, establishing bases in Libya, and planning external attacks on the United States," Mr Peter Cook, the Pentagon press secretary, said in a statement, using another acronym for the militant group.

NEW YORK TIMES