BEIRUT (AP) — Islamic State militants attacked a string of predominantly Christian villages in northeastern Syria on Saturday, touching off heavy clashes with Kurdish militiamen and their local allies, activists said.

The attack began around dawn and targeted at least three villages near the town of Tal Tamr along the Khabur River in Hassakeh province. The Islamic State group kidnapped more than 220 Assyrian Christians from the same area last month after overrunning several farming communities on the southern bank of the river.

The fighting Saturday was focused in villages on the northern bank of the river as the militants press to capture Tal Tamr, a strategic crossroads some 35 kilometers (20 miles) from the city of Hassakeh, said Osama Edwards, director of the Assyrian Network for Human Rights.

"The battles are now very intensive, very violent," said Edwards, who is based in Sweden. "Tal Tamr is the main goal of the Islamic State, to give them the corridor to the eastern border to Iraq."

The Britain-based Syrian Observatory for Human Rights also reported the fighting around Tal Tamr, which it said was coming under Islamic State artillery fire. Observatory director Rami Abdurrahman says the Islamic State extremists initially made gains before Kurdish fighters backed by local Assyrian militiamen pushed them back.

The Observatory said at least eight militants were killed in the fighting and an unknown number of Kurds.

The Assyrians are an indigenous Christian people who trace their roots back to ancient Mesopotamia.

Also Saturday, Syrian state media said government airstrikes this week in the central province of Hama killed a local leader of the Islamic State group. It identified the slain militant as Deib Hdeijan al-Otaibi, also known as Abi Ammar al-Jazrawi, and said a convoy of vehicles was also destroyed in the air raids.

Observatory director Abdurrahman also said al-Jazrawi had been killed, along with at least 25 other Islamic State fighters.