Suspected ISIS shooters assaulted a Ramadan meeting in eastern Syria held by a former official of a Kurdish-led party, killing seven people and wounding four more, opposition activists claimed Thursday.

According to the Syrian Observatory for Human Rights and the Euphrates Post news website, the attack on Thursday night in the Abu Khashab district of Deir el-Zour province targeted the residence of a former spokesman for the Kurdish-led Syrian Democratic Forces.

According to the Euphrates Post, the shooters arrived on motorbikes. They opened fire while the party was eating iftar — the meal that breaks the fast during the Muslim holy month of Ramadan — at the residence of former SDF spokesman Nouri Hameesh.

Three years after ISIS lost its final sliver of territory, its sleeper cells have increased their attacks in recent months, primarily against the SDF but also against Syrian government forces.

At its height, ISIS's self-styled caliphate controlled roughly a third of Iraq and Syria. The subsequent war against them lasted several years, claimed thousands of lives, and destroyed significant swaths of both bordering countries.