ISIS killed 10 pro-government fighters and wounded six others in an attack in eastern Syria late on Monday, a war monitor has said.
The militants attacked military vehicles and checkpoints belonging to the regime and local militias in its former stronghold of Raqqa, according to the Syrian Observatory for Human Rights.
The Islamist extremists held the positions for several hours, killing 10 members of the regime's forces and allied militias.
Six others were wounded, some of whom are in a serious condition.
Since its removal from its last stronghold of Baghouz in March 2019, ISIS has vastly diminished in power, but the terror group still maintains a presence in mostly rural parts of Iraq and Syria, where remnants stage attacks against security forces and civilians.
It has also carried out suicide bombings in large cities, including one in Baghdad which killed 35 people in 2021.
Its leader Abu Hussein Al Husseini Al Qurashi was killed in clashes with extremist group Hayat Tahrir Al Sham in Syria's Idlib province, ISIS confirmed last week.
There was no immediate comment on Monday's attack in Syrian state media.
A total of 196 regime troops and allied militiamen have been killed by ISIS since the start of the year in 105 attacks across desert regions of Deir Ezzor, Raqqa, Homs, Aleppo, Suweida and Hama, according to SOHR estimates.
This figure includes 37 members of Iran-backed militias, which have staunchly supported President Bashar Al Assad during the civil war.
At least 157 civilians have also been killed.
International coalition troops remain in Syria to ensure an “enduring defeat” of ISIS, working closely with the Kurdish-led Syrian Democratic Forces (SDF) in the north-east.
SDF troops are also often targeted by ISIS sleeper cells.
The US has warned the terror group could return to Syria within one to two years if Washington withdraws.
