A young German woman fighting alongside Kurdish forces in Syria was killed over the weekend in clashes with Islamic State fighters, Kurdish officials and a Turkey-based communist group said on Monday.

The Kurdish forces, backed by U.S. airstrikes and local rebel fighters, have been battling Islamic State in northern Syria since the al-Qaida offshoot captured large tracts of land along the border with Turkey.

The woman, Ivana Hoffmann, was killed in a village near the town of Tel Tamr in northeastern Syria, Kurdish official Nasir Haj Mansour said. She had joined female Kurdish fighting units, known as the YPJ, two to three months ago, he said.