KANDAHAR, Afghanistan -- Gunmen in southern Afghanistan kidnapped 30 members of the Hazara ethnic community, authorities said Tuesday.

The 30 people were kidnapped from two vehicles on a major road in Zabul province, provincial Gov. Mohammad Ashraf said. He said authorities were trying to find those kidnapped, some of whom may be government officials.

Though no group immediately claimed responsibility for the attack nor demanded a ransom, deputy police chief in Zabul province told CBS News that militants of the Islamic State of Iraq and Syria (ISIS) were behind the abductions, which he said took place on the Kabul-Kandahar highway on Monday night.

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Deputy police chief Ghulam Jilani Farahi told CBS News' Ahmad Mukhtar over the phone that ISIS fighters "stopped two passenger buses traveling from Kandahar to Kabul and took 11 people from one bus and 20 people from the second bus."

He said all of those abducted were Hazara Shiite Muslims.

Farahi said a search and rescue operation was underway in the Zabul province.

Abdul Khaliq Ayubi, a local government official, said the gunmen all wore black clothing and black masks.

"We contacted the Taliban through tribal elders but Taliban said they are not behind this kidnapping," Ayubi told CBS News.

He said the drivers of both buses had told authorities that the kidnappers spoke in a foreign language.

"We believe they are Daesh (ISIS)," Ayubi said, adding that he had received reports of ISIS activity in his district recently and had reported it to provincial leaders.

If it's confirmed that ISIS was behind the abductions, the bus passengers would be the first hostages held by the group in Afghanistan.

Afghan officials only confirmed in January that ISIS was operating in southern parts of the country. The following month, a drone strike killed the top recruiter for ISIS in Afghanistan, according to local officials, marking the first such attack on the extremist group in a volatile country where it has a small but growing following.

U.S. officials said a total of eight people were killed in the drone strike, but could not confirm the ISIS recruiter's death. The deputy governor of the southern Helmand province identified the recruiter as Abdul Rauf, saying he and others were killed when a drone-fired missile struck their car.

Afghan tribal leaders and Western intelligence analysts told The Associated Press in January that Abdul Rauf was the top ISIS recruiter in Helmand. Rauf had previously been held in the Guantanamo Bay detention center in Cuba for his involvement with the Taliban.

The Hazara, some 9 percent of Afghanistan's population, are a largely Shiite ethnic minority in predominantly Sunni Afghanistan. The group has been targeted by the Taliban and other Sunni extremists in Afghanistan and neighboring Pakistan.

The predominantly ethnic Pashtun Taliban persecuted the Hazara minority during their five-year rule that imposed a radical interpretation of Islamic law.