ISIS fighters encircled in southern Syrian volcanic field

The last remaining ISIS fighters in southern Syria are surrounded in a volcanic field in the desert near the city of Sweida.

In the past few days, Syrian government forces have encircled the Al Safa volcanic field, a striking plateau of rolling black hills that is visible from space.

The Syrian army launched a major offensive to recapture the stretch of desert where the field lies, east of Sweida, after a devastating attack on the Druze city by ISIS fighters last month that left more than 200 dead.

The militants captured 30 civilians during the attack on July 25, mostly women and children. The group executed a 19-year-old student and an elderly woman died of a heart attack during her captivity.

The fate of the remaining hostages is unknown. The kidnappers have released videos of the captives asking for military operations in the area to stop, and local sources claim they have also asked for a cash ransom.

The attack on Sweida sent shockwaves through the 700,000 minority Druze community, most of whom live in southern Syria, and caused anger at the government for not protecting the city.

The Syrian army has faced little resistance recapturing the area around the Safa field. Government news outlets reported that ISIS were using hit-and-run attacks, while a small number of casualties had been caused by IEDs and landmines.

Al Safa is part of the much larger Harrat Ash Shamah volcanic field, which covers 49,209 square kilometres of southern Syria, Israel, Jordan and Saudi Arabia. The circular black smudge that distinguishes Safa in satellite images is thought to have been formed by a boiling lava lake that erupted about 1850.