ISIS militants attacked Ghweran prison in Hasaka province late on Thursday, attempting to free prisoners in the jail.
The SDF military source told Reuters that seven members of the U.S.-backed forces and a member of Asayish (security) forces were killed in the attack.
The SDF said it had detained 89 militants in the area of the prison, where clashes were continuing, according to Reuters.
It was the second time since December that Islamic State had attacked the prison in an effort to free inmates.
The SDF military source said the attack on the prison coincided with Islamic State attacks in Iraq and what he described as movements by the militant group in the eastern Syrian province of Deir al-Zor.
“Islamic State is trying to impose its control on the area and to revive its organization once again,” Reuters quoted the source as saying.
Earlier on Friday, ISIS militants attacked an Iraqi military base in Diyala province, killing 11 soldiers.
Islamic State controlled swathes of Syria and Iraq until it was driven from the territory in 2017-19 by adversaries including a U.S.-led coalition, the SDF, and Iraqi security forces. Islamic State cells continue to carry out attacks in both countries.
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