The death toll in the bombing of a mass protest in Kabul has risen to 61, an Afghan official said.

Dr Waheed Majroeh, the head of international relations for the ministry of public health, said 207 people were also wounded by the blast, which was claimed by the Islamic State group.

The bombing struck a group of ethnic Hazara demonstrators who had been marching through Kabul.

A statement reported by the IS-linked Aamaq online news agency said two IS militants detonated their explosive vests amid the crowds of minority ethnic Hazara demonstrators.

Hazaras are predominantly Shiite Muslims, and IS views all Shiites as apostates. Shortly before the IS statement, the Taliban’s spokesman denied any Taliban involvement in the blast.

The Taliban have been waging a vicious insurgency against the Kabul government for 15 years, since their regime was overthrown by the US invasion in 2001.

The marchers were demanding that a major regional electric power line be routed through their impoverished home province. Most Hazaras are Shiite Muslims but most Afghans are Sunni.

Eyewitness Ramin Anwari described seeing up to eight bodies in the Demazang area, where protesters were preparing to set up a camp after a four-hour march.

One march organiser, Laila Mohammadi, said she arrived at the scene soon after the blast and saw “many dead and wounded people”.

Footage on Afghan television and photographs posted on social media showed a scene of carnage, with numerous bodies and body parts spread across the square.

Angry demonstrators sealed some of the area around the square, and prevented police and other security forces from entering. Some threw stones at security forces.

President Ashraf Ghani released a statement condemning the blast.

“Peaceful demonstrations are the right of every citizen of Afghanistan and the government will do everything it can to provide them with security,” said Mr Ghani.

His spokesman, Haroon Chakhansuri, said Mr Ghani would appear on live television later in the day.

Amnesty International issued a statement saying the “horrific attack” on the Hazara demonstration “demonstrates the utter disregard that armed groups have for human life”.

“Such attacks are a reminder that the conflict in Afghanistan is not winding down, as some believe, but escalating, with consequences for the human rights situation in the country that should alarm us all,” it quoted Champa Patel, Amnesty’s South Asia director, as saying.

At the height of the march, demonstrators chanted slogans against Mr Ghani and chief executive Abdullah Abdullah, shouting “death to discrimination” and “all Afghans are equal”.

The so-called TUTAP line is backed by the Asian Development Bank with involvement from Turkmenistan, Uzbekistan, Tajikistan, Afghanistan and Pakistan.

The original plan routed the line through Bamiyan province, in the central highlands, where most of the country’s Hazaras live. That route was changed in 2013 by the previous Afghan government.

Leaders of the marches have said that the rerouting was evidence of bias against the Hazara community, which accounts for up to 15% of Afghanistan’s estimated 30 million people.

They are considered the poorest of the country’s ethnic groups, and often complain of discrimination. Bamiyan is poverty-stricken, though it is largely peaceful and has potential as a tourist destination.

The spokesman for Mr Ghani said the central government shared intelligence with the organisers of the protest march in Kabul that was bombed, warning that the marchers faced a possible “terrorist attack”.

Mr Chakhansuri revealed government officials warned the march organisers that they risked attack, saying: “We knew that terrorists wanted to bring sectarianism to Kabul, and cause splits within our community.”

He said the president will meet leaders of the Hazara demonstrators later.