Update: The death toll in the suicide attack on Kabul has risen to 81 people, according to The Associated Press, making the bombing the deadliest attack to hit Kabul in 15 years. An additional 231 people have been wounded. This story was originally published at 10:45 a.m. EDT. An attack on a protest march in the Afghan capital has left 61 dead and hundreds wounded, The Associated Press reports, with officials saying the death toll is likely to rise. Thousands of members of Afghanistan’s Shia Hazara minority were marching in Kabul’s Deh Mazang square protesting the location of a new power line, which they said bypasses areas needing electricity, when an explosion ripped through the crowd. The attack is the worst in months for the city, with the highest death toll since a bombing in April that killed 60. ISIS claimed responsibility for the attack via its Amaq news agency, saying that the attack was carried out by two suicide bombers with explosive belts. The Taliban, which has carried out other bombings in the area, denied involvement with the attack via a spokesman. The bombing came in spite of tight security measures, according to Reuters, which included helicopter patrols and the sealing of the city center. A presidential spokesman told The Associated Press that the government had received intelligence warning of an attack and had warned the organizers. He said that one of the bombers was shot by police before the attack and that three security personnel had been killed. Afghan President Ashraf Ghani condemned the attack in a statement shared with The AP. "Peaceful demonstrations are the right of every citizen of Afghanistan and the government will do everything it can to provide them with security," he said.