At least nine people were killed Saturday in an attack claimed by the Islamic State group targeting forces loyal to strongman Khalifa Haftar in southern Libya, officials said.

IS fighters, "backed by criminal groups and mercenaries", launched a dawn assault on a military training camp in the southern city of Sebha, which is controlled by Haftar's forces, the city's mayor Hamed al-Khayali told AFP.

"The attack left nine dead ... some of whom had their throats slit and others who were shot dead," he said.

A spokesman for the Sebha Medical Centre confirmed it had received nine dead bodies.

IS claimed responsibility for the attack in a statement distributed through social media, saying it had targeted "Haftar's heretical militia" and freed prisoners held on the base.

Sebha is controlled by Haftar's self-proclaimed Libyan National Army, which opposes the UN-recognised Government of National Accord based in Tripoli.

A power struggle between the GNA and a parallel administration supported by Haftar in the east has left the country's vast desert south a lawless no-man's land.

The rugged territory, which shares borders with Algeria, Niger, Chad and Sudan, has become a haven for jihadists and other armed groups.

The LNA in mid-January announced the start of an offensive intended to "purge the south of terrorists and criminal groups", including rebels from Chad.

On April 4 it began another assault aimed at capturing the capital, leading to fierce fighting on the city's doorstep.

(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)