Three brothers have been beheaded in restive eastern Afghanistan, officials said Monday, blaming the gruesome executions on Islamic State group fighters.

The men aged 19, 24 and 27 were taken from their home and killed by IS on Sunday night in Chaparhar district in Nangarhar province, provincial governor spokesman Ataullah Khogyani told AFP.

Nangarhar borders Pakistan and is a stronghold for IS militants.

Two of the brothers recently graduated from medical school and the third was still at university, Khogyani said, adding the boys' father was also killed by IS last year.

“Their bodies were found in Chaparhar district where they lived,” said the spokesman.

Provincial police spokesman Hazrat Hussain Mashreqiwal confirmed the brutal murders and said an investigation had been launched.

“They were taken out of their house by armed men and their beheaded bodies were found by villagers near their house,” Mashreqiwal told AFP.

IS first emerged in Afghanistan in 2014 as NATO combat troops withdrew from the country and handed over responsibility to Afghan security forces.

Despite being far smaller than the Taliban, IS has claimed responsibility for devastating attacks in Kabul and elsewhere in the country.

On Sunday, IS claimed a suicide attack in a large crowd outside a voter registration centre in Kabul that killed 57 people and wounded more than 100.

Some Western and Afghan officials believe IS has received help from the Haqqani Network, a brutal wing of the Taliban.

Following an intense air and ground campaign by Afghan and US forces in Nangarhar, IS spread beyond its stronghold to the northern province of Jowzjan where it has also come under pressure.

Earlier this month top IS commander in northern Afghanistan Qari Hikmatullah was killed in an airstrike.