MAZAR-I-SHARIF, Afghanistan, Jan. 21 (Xinhua) -- At least 18 pro-government militiamen were killed following a Taliban ambush attack in Afghanistan's northern province of Balkh overnight, a local official said Sunday.

The incident occurred in village Bozboy, Sholgra district, Saturday night when Taliban militants stormed a security checkpoint, resulting in a clash that left 18 members of Local Uprising Groups dead, district Chief Sarrajuddin Abid told Xinhua.

Among those killed was Hajji Hamidulla, a local leader and divisional commander of the local anti-Taliban fighters, and his son Obidullah, who was serving in ranks of Afghan police, the source added.

An investigation was still on, he noted.

The Taliban has claimed responsibility. Zabihullah Mujahid, a purported Taliban spokesman, twitted that a Taliban sympathizer was among the militias and he had facilitated the attack.

He stated that one Taliban fighter was killed and another wounded during the clash.

Fighting has escalated in Afghanistan as the Taliban insurgency spreads from its traditional strongholds in the south and east to the once peaceful region in the north, where Taliban have been recruiting from among the youth.

The Taliban outfit and Islamic State (IS) terror group often target civilians and religious clerics as well as local leaders for their support to the Afghan government and the U.S.-led forces stationed in the country.