The US launched an airstrike against an alleged Islamic State training camp in Libya, with local hospital sources saying 40 people were killed.
The US Department of Defence said Friday the strike targeted Noureddine Chouchane, a "senior facilitator" of Tunisian origin. Chouchane was a key suspect in the Bardo Museum attack in Tunis last year, which killed more than 20 people, including tourists.
"This strike demonstrates we will go after ISIL whenever it is necessary, using the full range of tools at our disposal," said a statement, which added that the bombing would have "an immediate impact" on the extremist group's operations.
A hospital in Sabrata city, 40 kilometres west of the capital Tripoli, received bodies of people of various Arab and African nationalities, including Libyans, a local medical source said.
The attack was in an area suspected to be used by Islamic State, Sabrata Mayor Hussien Al-Daoudi told Libyan state television. The area, close to the Tunisian border, is seen as a hotbed for foreign nationals who have joined Islamic State.
There is growing concern and evidence that Islamic State is boosting its presence in Libya, which was thrown into chaos after the NATO-backed ouster of dictator Moamer Gaddafi in 2011, as it comes under pressure and cedes ground in both Syria and Iraq.
Islamic State already controls a long stretch of coastline around the city of Sirte, about 500 kilometres east of Tripoli. The group thrives in Sunni Muslim areas where states are weak.
Since the US-led coalition was launched in late 2014, Islamic State has lost 40 per cent of territory in Iraq and about 30 per cent in Syria, US Secretary of State John Kerry said this month.
The New York Times reported that plans for military action against Islamic State in Libya had been "stepped up amid fears that the terrorist group, is preparing to shift its headquarters from Syria to North Africa and threaten the Mediterranean."
However, at this time, it is not clear the US is embarking on a widescale operation in the North African nation or carrying out specific strikes.