IS late Friday used suicide bombers as part of a counter-attack against the Syrian Democratic Forces, backed by the US-led coalition against the jihadists, said the Britain-based Syrian Observatory for Human rights.
The Islamic State group has killed 60 US-backed fighters in Syria who are battling to oust the jihadists from their eastern holdout of Hajin on the Iraqi border, a war monitor said Saturday.
IS late Friday dispatched suicide bombers as part of a counter-attack against the Syrian Democratic Forces, said the Britain-based Syrian Observatory for Human rights.
The SDF fighters, who are backed by US-led coalition air strikes, were killed overnight, the Observatory said.
In a statement on the Telegram messaging app, IS said it had attacked the village of Sousa late Friday and detonated a car bomb near the village of Al-Baghuza further south, down the Euphrates river.
The SDF last month launched an offensive against the jihadists in the Hajin pocket on the eastern banks of the Euphrates, in Deir Ezzor province.
IS has staged a bloody fightback.
Since September 10, 270 SDF fighters and 496 IS jihadists have been killed in the offensive, the Observatory says.
The coalition estimates that 2,000 IS fighters remain in the Hajin area.
Last week, the Observatory said coalition air strikes had killed 41 civilians in Sousa, 10 of them children, on October 18 and 19.
But the coalition said it had targeted an IS command post on October 18, and denied carrying out any strikes in the area the following day.
IS overran large swathes of Syria and neighbouring Iraq in 2014, proclaiming a "caliphate" across land it controlled.
But the jihadist group has since lost most of that territory to various offensives in both countries.
In Syria, its presence has been reduced to parts of the vast Badia desert and the Hajin pocket.
Syria's war has killed more than 360,000 people since it erupted in 2011 with the brutal repression of anti-government protests.