KABUL, Aug. 7 (Xinhua) -- At least 50 civilians and security force members were killed during a heavy clash in Afghanistan's eastern province of Logar on Monday night, reported a local private news agency on Tuesday.

The clash started at midnight after Taliban militants stormed headquarters of Azra district and surrounding neighborhoods from different sides, Pajhwak Afghan News reported on its website.

Citing Abdul Wali Wakeel, a member of provincial council, the report said that 35 security personnel and civilians were killed during the clash and gunfight in the remote district while at least 15 police officers died in an ensuing friendly fire when U.S.-led NATO coalition forces conducted an airstrike on a police checkpoint in Azra.

"The militants were closing in on the district center and fierce gun-battles were underway in different parts of Azra, sharing a border with eastern Nangarhar province," the report said.

Several militants were also killed or wounded during the fighting.

Zabiullah Mujahid, a purported Taliban spokesman, claimed that Taliban fighters were advancing into the district administrative center by early Tuesday, according to the report.

Taliban militants, who ruled the country before being ousted in late 2001, renewed armed insurgency, killing government troops as well as civilians.

They have intensified armed attacks against security forces across the country since April 25 when the Taliban's so-called yearly rebel offensive started.

The Logar province, which is located 60 km south of national capital city Kabul, has been the scene of heavy clashes between security forces and Taliban since early this year.