A US air strike killed a suspected Islamic State militant in Libya on Tuesday, the US Africa Command said.

The strike into the northwestern town of Bani Walid was carried out in coordination with the UN-backed government based in Tripoli, it said in a statement.

It did not name what it called an "ISIS-Libya terrorist" but residents identified him as Walid Bu Hariba who hails from the central city of Sirte where Islamic State had its main base in the anarchic North African country until 2016.

Residents had earlier reported an air strike on a car in Bani Walid in which an Islamic State militant had been travelling. Photos on social media showed a white pick-up truck purportedly hit by a projectile.

Some militants have sought to regroup in Libya's vast desert and in towns such as Bani Walid, located some 150 km (93 miles) south of the capital Tripoli.

In June, the United States said it had conducted two precision air strikes near Bani Walid, killing four Islamic State militants and an al Qaeda fighter.

The United States gave air support to Libyan forces that drove Islamic State from Sirte in 2016, and has continued to launch occasional strikes on suspected militants in Libya since the end of that campaign.

The Tripoli administration exercises little control in the OPEC member country, which has been plagued by turmoil since rebels overthrew Muammar Gaddafi in 2011.