Mine hit vehicle packed with agricultural workers heading out to pick desert truffles, according to police.

At least 20 people have been killed in Syria when a landmine planted by the Islamic State of Iraq and the Levant (ISIL or ISIS) exploded under a van carrying farm workers, state-run SANA news agency reported.

The blast took place near the central town of Salamiyeh in Hama province on Sunday morning, SANA said, and was caused by explosives left behind by ISIL.

Citing local police, the news agency said the mine hit a vehicle packed with agricultural workers heading out to pick desert truffles.

The explosion was the second such incident since February 8 when a landmine planted by ISIL in rural Hama exploded killing seven civilians.

ISIL fighters have been driven out of virtually all the territories they once held in Syria and neighbouring Iraq, but the group left behind countless bombs and booby traps, and large areas have yet to be cleared.

The group’s fighters are now cornered by the US-backed Syrian Democratic Forces (SDF) in a small area near the Iraqi border.

Battle for Baghouz

An estimated 300 fighters are besieged in the village of Baghouz, hemmed in by the Euphrates River and the SDF – a Kurdish-led militia spearheading the fight against ISIL following an intense push since September.

Thousands of civilians have fled the area held by the group in recent weeks.

The presence of so many civilians – and possibly senior members of the group – in Baghouz has surprised the SDF and slowed down ISIL’s territorial defeat in eastern Syria.

Baghouz represents the last concentrated ISIL force in Syria’s war, which has killed hundreds of thousands of people and displaced millions since 2011.

Beyond Baghouz, ISIL retains a presence in the vast Syrian desert and continues deadly attacks in the SDF-held territory.

‘Mass influx’

The SDF warned on Sunday they are struggling to cope with an outpouring of ISIL fighters and their families. They have evacuated nearly 5,000 men, women and children since Wednesday.

“The numbers of foreign fighters and their relatives that we are holding is increasing drastically,” Kurdish foreign affairs official Abdel Karim Omar told AFP news agency.

“Our current infrastructure can’t handle the mass influx,” he said.

Syria’s Kurds have repeatedly called on foreign countries to repatriate their citizens, but most have been reluctant to allow battle-hardened soldiers and their relatives back home over security concerns.

Omar said SDF “detention centres can’t accommodate all the fighters”.