Islamic State launched a bomb and gun attack on a Western-backed Syrian rebel camp near the Jordanian border on Wednesday, according to the rebels who said they had killed at least 30 of the attackers and suffered at least three casualties themselves.

A suicide bomber rammed an explosive-laden vehicle into the camp belonging to the Forces of Martyrs Ahmad al-Abdo rebel group in a sparsely populated desert area near where the borders of Syria, Jordan and Iraq meet, the rebels’ spokesman, Saeed Saif, said. They then attacked several rebel outposts.

“We repelled the attack by Daesh (Islamic State) on several areas and they failed to make any progress and have retreated,” Saif told Reuters.

The Force of Martyrs Ahmed al-Abdo was one of the earliest Free Syrian Army (FSA) groups to get U.S.-made anti-tank missiles and is one of the groups aligned on the so-called Southern Front that a coalition of Western and Arab countries support.

That backing is part of a strategy of preventing opposition-held southern Syria and the south-eastern desert area falling into the hands of radical jihadist groups.

The group’s leader, Saleem Bakour, was killed in June by a suspected Islamic State militant.[nL8N1914IU ]

Islamic State claimed a suicide bomb attack launched from the same area in June when a car crossed into Jordan and killed seven Jordanian border guards.