At least 10 Syrian army soldiers, including an officer, were killed in clashes with Islamic State fighters on Tuesday in a rare ground confrontation between the two sides in the eastern Deir al-Zor province, a monitoring group said.

The clashes took place on Huwiejat Sakr, a small island in the Euphrates River located just southeast of Deir al-Zor city, according to the Britain-based Syrian Observatory for Human Rights.

It is close to a government-controlled military air base, the last major outpost held by the Syrian army in the province. […]