"A horrific video was released yesterday showing kidnappers who associate themselves with Daesh [the Arabic acronym for "Islamic State"] brutally martyring several white-bearded tribal elders and villagers with explosives," the Taliban said in a statement.

The Taliban has often been accused of brutality against Afghan government forces and foreign troops throughout its 14-year insurgency following the US invasion of Afghanistan in 2001 that led to its ouster.

"This offense and other such brutal actions by a few irresponsible ignorant individuals under the guise of Islam and Muslims are intolerable," the Taliban said.

Rivalry

However, recent incursions by the "Islamic State" militant group into the Taliban's home turf have resulted in a vicious rivalry among the militant groups.

The Taliban concluded its statement by calling on "leaders" in Afghanistan's Nangarhar province, the area where the video was apparently shot, to "punish" the "Islamic State" militants.

"The Islamic Emirate [the Taliban's official name] orders its leaders in the area to find and punish the perpetrators of this heinous act in light of sublime Shariah Law," the Taliban said, referring to its strict version of Islamic jurisprudence.

Preaching a more extreme version of Islamist militancy, the "Islamic State" has gained traction in Afghanistan, with some defecting members of the Taliban joining its ranks.

The Taliban's announcement of its enigmatic leader Mullah Omar's death in July and the rushed declaration of his successor Mullah Akhtar Mansour have led to a bitter power struggle among the group's leadership.

ls/kms (AFP, Reuters, dpa)