Land mines left behind by the Islamic State group in central Syria went off in two different locations on Monday, killing 10 workers as they were collecting truffles in the countryside and wounding 12, state media reported.

According to Syria's state news agency SANA, the two mines exploded east of the central town of Salamiyeh. All the casualties were taken to a hospital in the town, the report added. It wasn't immediately clear what had triggered the explosions.

It is not uncommon for mines left behind years ago, when IS controlled large parts of Syria, to go off inadvertently, usually when stepped on, inflicting casualties.

IS was driven out of all the territory it once held in Syria and neighboring Iraq in 2019, but the extremists left behind countless bombs and booby traps, and large areas have yet to be cleared. The militant group’s sleeper cells still carry deadly attacks both in Syria and Iraq.

SANA said the first explosion on Monday killed nine people and wounded two while the second killed one person and wounded 10.

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Earlier this month, IS sleeper cells attacked workers collecting truffles near the central town of Sukhna, killing at least 53 people, mostly workers but also some Syrian government security forces.

The truffles are a seasonal delicacy that can be sold for a high price. Since the truffle hunters work in large groups in remote areas, IS militants in previous years have repeatedly preyed on them, emerging from the desert to abduct them, kill some and ransom others for money.