Militants claiming allegiance to the Islamic State were behind the Monday abduction of 30 members of the ethnic Hazara minority in southern Afghanistan, according to local officials.

Gunmen reportedly seized the hostages after stopping two buses traveling on the Kabul-Kandahar highway through Zabul province. The deputy police chief in Zabul province told CBS News that Islamic State loyalists were responsible for the abductions.

The gunmen "took 11 people from one bus and 20 people from the second bus," said Ghulam Jilani Farahi, the deputy police chief, adding that a search operation was underway. VICE News could not independently verify those claims.

Abdul Khaliq Ayubi, a government official, told CBS the militants wore the black clothes and masks associated with fighters for the self-proclaimed caliphate, adding that witnesses said they spoke a different language.

Reports of the Islamic State's presence in Afghanistan have become more frequent in recent months — particularly after some high-ranking members of the Afghan and Pakistani Taliban switched ranks and pledged allegiance to leader Abu Bakr al-Baghdadi.

Militants claiming affiliation with the radical Sunni group have also engaged in fighting against local Taliban members and reportedly killed a Taliban commander in Logar province. One account described armed men forcing their way into local homes, smashing television sets, antennas, and recording devices and warning residents against watching television.

Despite the recent incidents, the Islamic State's presence in Afghanistan remains small — and logistical ties to the group's strongholds in Iraq and Syria appear to be limited.

Earlier this month, Mullah Abdul Rauf, a former Guantanamo detainee and Taliban commander who defected to the Islamic State, was killed in a drone attack.

All the men kidnapped on Monday were Hazara, a Shia minority group often targeted by the Taliban, who are mainly Sunni members of the Pashtun ethnicity. Last July, 16 Hazaras were executed by Taliban militants after they were separated from other passengers traveling on a bus through the central province of Ghor.

"We contacted the Taliban through tribal elders but Taliban said they are not behind this kidnapping. We believe they are Daesh," Ayubi told CBS about the latest abduction, using the acronym for the Islamic State's full Arabic name.

Anand Gopal, an analyst and author of a book on the US war in Afghanistan, told VICE News earlier this year that reports of the Islamic State in Afghanistan should be treated with caution because of the historic weakness of foreign-linked Islamic groups in the country.

"Afghan officials have a tendency to play up the ISIS threat as a way of trying to capture the West's flagging attention," Gopal said. "With that being said, however, it does appear that a few disgruntled Afghan Taliban members are rebranding themselves as ISIS."