The Taliban arrested four members of the rival militant Islamic State group north of the Afghan capital, their spokesman said Wednesday, and witnesses said two Taliban fighters were shot and killed in the country's east, raising the specter of a widening conflict.

Zabihullah Mujahid, the Taliban spokesman, said an operation was carried out on Tuesday night by the Taliban in Kabul province in which documents and weapons were seized. He provided no additional details.

Two Taliban members were shot and killed and three civilians were wounded Wednesday when unknown gunmen opened fire on a Taliban patrol in a vegetable market in the eastern city of Jalalabad, two witnesses said. A hospital official later said the local health facility received two dead bodies and two wounded men. They spoke on condition of anonymity for fear of reprisals.

The Islamic State group did not claim the market shooting, but has carried out similar attacks before in the area. Jalalabad in particular has emerged as a flashpoint in the rivalry between the Taliban and IS, with numerous attacks taking place there since the Taliban takeover of Afghanistan in mid-August.

The Taliban leadership has been grappling with a growing threat from the local IS affiliate, known as the Islamic State in Khorasan. IS militants have ramped up attacks to target their rivals, including two deadly bombings in Kabul.

IS claimed it targeted a vehicle carrying Taliban members in Kunar province on Tuesday night. It said a Taliban reinforcement patrol rushed to the area to help but IS fighters clashed with them, allegedly killing and wounding "many."

IS re-emerged in Afghanistan in 2020 after being weakened by a heavy U.S. bombing campaign in the eastern part of the country in 2019. The group claimed responsibility for Sunday's bombing at Kabul's Eid Gah Mosque which killed five civilians.

It has also claimed responsibility for the horrific Aug. 26 bombing that killed at least 169 Afghans and 13 U.S. military personnel outside the Kabul airport in the final days of the chaotic American pullout from Afghanistan.

The Taliban have since launched many raids to root out IS cells.