BEIRUT, Lebanon - A blast from a landmine left by the Islamic State group killed at least 13 civilians foraging for truffles in the Syrian desert, a war monitor said.

"Thirteen civilians, including women... were killed when a landmine left by the IS group exploded while they were searching for truffles" in the desert in Raqa province, said the Syria Observatory for Human Rights.

The Syrian desert is renowned for producing some of the best quality truffles in the world, which fetch high prices in a country battered by 13 years of war and a crushing economic crisis.

Authorities frequently warn against the high-risk practice.

But every year between February and April, foragers risk their lives to collect the delicacies in the vast Syrian desert, or Badia -- a known hideout for jihadists that is also littered with landmines.

In March 2019, IS lost its last scraps of territory in Syria following a military campaign backed by a US-led coalition, but jihadist remnants continue to hide in the desert and launch deadly attacks.

They have used such hideouts to ambush civilians, Kurdish-led forces, Syrian government troops and pro-Iran fighters, while also mounting attacks in neighbouring Iraq.

Syria's war has claimed the lives of more than half a million people and displaced millions since it erupted in March 2011 with Damascus's brutal repression of anti-government protests.