KABUL — Three women and a child were among seven people beheaded by suspected ISIS-linked militants in southern Afghanistan, officials told NBC News on Monday.

Their bodies were taken to a hospital on Sunday after fighters who were holding them fled during an assault by rival militants in Zabul province, Deputy Governor Massoud Bakhtawar told NBC News. It was not known exactly when the victims, all members of the Hazara minority, were killed.

“We are not sure who beheaded them, but they were abducted ... by foreign militants loyal to Daesh," Bakhtawar said, using an alternate name for ISIS.

The deaths came amid escalating fighting between rival Taliban factions in the province.

At least 80 people have died in Zabul over the weekend, both fighters and civilians, according to two Taliban commanders who spoke to NBC News on condition of anonymity.

Related: Taliban Splinters as ISIS Makes Inroads in Afghanistan

According to Gul Islam, a spokesman for Zabul's governor, 53 militants have been killed in “very heavy fighting” in the area. Officials did not say how many civilians may have been killed.

Journalists cannot work safely in the area and there was no way to independently verify the differing casualty reports.

The announcement in July that reclusive long-time leader Mullah Omar was dead sparked a leadership battle within the Taliban, with his deputy Mullah Akhtar Mohammad Mansour being named leader over the objections of many militants.

Around 400 ISIS-linked Uzbeks were fighting with a rival faction led by Mullah Mohammad Rasool Akhund in the province, according to a spokesman for the group, Abdul Manan Niazi.

Militants linked to ISIS have been making inroads in the regions, luring members of the Taliban who are unhappy with the Afghan group’s leadership.

Related: Tens of Thousands Flee Taliban, ISIS Violence

A senior member of Pakistan's intelligence branch who spoke on condition of anonymity because he is not authorized to speak to the press told NBC News the split was largely due to divisions over peace talks.

"The more you push the Taliban, the more split they will get about joining up with ISIS or talking," he said.