The terrorist Islamic State group has claimed responsibility for a series of deadly bombings targeting the Taliban terror group vehicles in eastern Afghanistan on Sunday and Monday.

The claim, published late Sunday and confirmed on Monday afternoon, on the terror group’s media arm, the Aamaq news agency, signals a growing threat to the Taliban by their long-time rivals.

At least eight people, including several Taliban terrorists, were killed in the attacks on Sunday and Saturday in the provincial city of Jalalabad, an IS stronghold.

The Taliban terror group seized control of Afghanistan in a blitz campaign last month, overrunning the capital of Kabul while U.S. and NATO were in the final phase of withdrawing their troops. The last foreign soldiers left Aug. 30.

The Taliban now face major economic and security challenges in trying to govern Afghanistan, and an accelerated campaign of IS attacks will further complicate those efforts. The Taliban and IS terrorists were enemies before foreign troops left Afghanistan.

Both groups subscribe to a harsh interpretation of Islam, but the Taliban terrorists appeared to have focused on taking control of Afghanistan, while IS affiliates in Afghanistan and elsewhere call for global jihad.