Islamic State militants are reported to have regained control of a town near their northern Syrian stronghold of Raqqa from Kurdish-led forces.
The Syrian Observatory for Human Rights, a UK-based monitoring group, said jihadists overran Ain Issa and nearby villages before noon on Monday.
But a spokesman for the Kurdish Popular Protection Units (YPG) said it was still resisting the IS assault.
YPG fighters and allied Syrian rebels only seized Ain Issa two weeks ago.
The town, only 50km (30 miles) north of Raqqa, is situated at an intersection of the main roads from the de facto of the caliphate proclaimed by IS to other areas it controls in Aleppo province, to the west, and Hassakeh province, to the east.
In recent weeks, IS has launched several deadly counter-attacks against the Kurds.