BEIRUT: Rival groups are reporting intense battles in eastern Syria between the Islamic State group and US-backed fighters.
The US-backed Syrian Democratic Forces says the fighting on Thursday is over the village of Sousah where a sandstorm has caused bad visibility.
The Britain-based Syrian Observatory for Human Rights said the fighting began on Wednesday, when IS launched an offensive against the opposition group, killing 10 of them.
The fate of 35 other opposition fighters is unknown.
The Observatory said 18 IS gunmen have been killed while the IS-linked Aamaq news agency reported 18 deaths among SDF fighters.
Sousah is in the last pocket held by IS in Syria that the SDF has been trying to capture since last month.