Islamic State group said on Monday it was behind a blast in a small town in southern Libya on Saturday, the militant group's first attack in the country for at least a year.

The blast targeted a security point at the entrance to Taraghin, 780 km (590 miles) south of Tripoli, but did not cause any casualties, a resident said.

A local military commander, Abdesselam Shanqala, said the explosives were concealed in a vehicle belonging to the eastern-based Libyan National Army (LNA) and there were no casualties.

An LNA military source said Islamic State group was growing more active in the south after the arrest of one of its commanders.

The last attack in Libya that Islamic State group said it was responsible for took place in May last year on a pipeline in the south.

The group became active in Libya after the turmoil that followed the overthrow of Muammar Gaddafi in 2011, and it took control of the coastal city of Sirte in 2015 but lost it in late 2016 to local forces backed by US airstrikes.