A group of IS attackers attacked around 75 people who were gathering truffles in the area around Palmyra, in the eastern part of the Homs region, according to the Syrian Observatory for Human Rights (SOHR), which monitors the Syrian war from Britain.
Ten civilians and one person from the government forces were killed, according to SOHR, which however adds that several people are still missing.
The attack was reported by the state-run Syrian news agency Sana. IS is also accused there, but the number of dead is initially written at only four civilians.
The remaining IS-affiliated groups remaining in Syria have continued to carry out sporadic attacks against government forces and Kurdish forces, as well as in Iraq.