The two-pronged attack on the northeastern city of Hassakeh and the border town of Kobani came two days after an Islamic State spokesman acknowledged that the group might lose some battles but would not be defeated.
The spokesman, Abu Muhammad al-Adnani, had urged militants to strike back at their foes during the Muslim holy month of Ramadan and "shake the ground beneath them."
The early morning assault by IS captured part of Hassakeh, which has long been divided between Syrian Kurds and the military forces of President Bashar Assad.
