Al-Qaeda’s Syrian affiliate Al-Nusra Front launched an offensive Friday on the headquarters of a new US-formed anti-government militant group in the country’s north, leaving at least 11 dead

Al-Qaeda's Syrian affiliate Al-Nusra Front launched an offensive Friday on the headquarters of a new US-formed anti-government militant group in the country's north, leaving at least 11 dead, a monitor said.

The attack came one day after the Takfiri group kidnapped eight militants from Division 30, who had been trained and equipped by Washington, said the Syrian Observatory for Human Rights monitoring group.

"Al-Nusra attacked at dawn the headquarters of Division 30, near the town of Azaz in the northern province of Aleppo," the Britain-based Observatory said.

Clashes broke out after the assault that killed five of Al-Nusra and allied militants, as well as six militants who were defending Division 30, said Observatory director Rami Abdel Rahman.

He said Al-Nusra launched the attack to seize weapons "given by Washington to the militants" but that the group had not been able to enter the base as clashes continued during the day.

In a statement posted on its Facebook page about the attack, Division 30 called on Al-Nusra to stop "spilling the blood of Muslims".

At least 54 members of Division 30 entered Syria in mid-July, equipped with 30 American-made all-terrain vehicles, arms, and ammunition.

Eight of them, including a commander, were kidnapped on Thursday by Al-Nusra in a village in Aleppo province, the Observatory said.