Afghanistan's interior ministry has said the death toll in a suicide bombing during a peaceful demonstration by members of the Hazara minority in Kabul has climbed to 80.
The ministry said in a statement that at least 231 people were wounded.
President Ashraf Ghani, who has condemned the blast, declared Sunday a day of national mourning.
In a live television address, he said: “I promise you I will take revenge against the culprits.”
“I have ordered the attorney general to set up a commission to investigate this incident.”
Graphic television footage from the site of the blasts showed many dead bodies lying on the road, close to where thousands of Hazara had been demonstrating over the route of a planned multimillion dollar power line.
It was not immediately clear how many bombs were involved in the attack.
Emergency vehicles were at the site and wounded were being carried away.
Much of the city centre had been sealed off with stacks of shipping containers and other obstacles as the march began earlier on Saturday, and security was tight with helicopters patrolling overhead.
Islamic State, also known as Isis, claimed responsibility for the attack, the group’s Amaq news agency reported.
“Two fighters from Islamic State detonated explosive belts at a gathering of Shi’ites in... the city of Kabul in Afghanistan,” Amaq said in a brief news alert.
If the claim is true it would be the first attack by the extremists in the Afghan capital.
The incident came some three weeks after a suicide bomber killed dozens of people in an attack on newly graduated police cadets that was claimed by the Taliban.
The Taliban has denied responsibility for Saturday’s attack.
“Opportunist terrorists went among the protesters and set off explosions that killed and wounded a number of our countrymen including security and defence personnel,” president Ashraf Ghani said in a statement.
Warned organisers
A spokesman for Mr Ghani said the central government shared intelligence with the organisers of the march, warning that they faced a possible “terrorist attack.”
Haroon 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.
Saturday’s demonstrators had been demanding the 500kV transmission line from Turkmenistan to Kabul be rerouted through two provinces with large Hazara populations, an option the government says would cost millions and delay the badly needed project by years.
Amnesty International issued a statement saying the “horrific attack” on the Hazara demonstration “demonstrates the utter disregard that armed groups have for human life”.
The Persian-speaking Hazara, a mainly Shia group estimated to make up about 9 per cent of the population, are Afghanistan’s third-largest minority but they have long suffered discrimination. Thousands were killed under Taliban rule.
The protest by a group whose leaders include members of the national unity government had put pressure on Mr Ghani, who has faced growing opposition from both inside and outside the government.
Russian president Vladimir Putin sent a message to Mr Ghani expressing readiness to fight all forms of terrorism together in the most active way, Russian media cited the Kremlin as saying.
“The head of the Russian state strongly condemned this cynical crime committed against peaceful citizens and reiterated readiness to continue the most active co-operation with the authorities and people of Afghanistan in fighting all forms of terrorism,” Russian media quoted a Kremlin statement as saying.
The White House condemned said: “This heinous attack was made all the more despicable by the fact that it targeted a peaceful demonstration.
“We remain committed to work jointly with the Afghan security forces and countries in the region to confront the forces that threaten Afghanistan’s security, stability, and prosperity.”
Agencies