A local reporter in Kandahar told Reuters that eyewitnesses had described three suicide attackers, one of whom blew himself up at the entrance to the mosque with the two others detonating their devices inside the building.

“The situation is very bad. Mirwais hospital is messaging and calling on young people to give blood,” he said, referring to a local hospital where dead and injured had been taken.

Photographs and mobile phone footage posted by journalists on social media showed many people apparently dead or seriously wounded on the bloody floor of the Imam Bargah mosque.

A health official gave figures of 33 dead and 73 wounded and said the final total could be higher. There was no immediate claim of responsibility for the attack. Interior ministry spokesman Qari Saeed Khosti of the ruling Taliban movement said authorities were collecting details. The blast took place just days after an attack claimed by Islamic State militants, which killed scores of Shi’ite worshippers at a mosque in the northern city of Kunduz. The full death toll from that attack has been estimated as high as 80.

Sunni Muslim fighters of Islamic State have repeatedly targeted Shi’ites in the past. The Taliban are also strict Sunni Muslims but have pledged to protect all ethnic and sectarian groups since sweeping into power in August as U.S. forces withdrew.

The embassy of Iran, Afghanistan’s neighbour and the region’s largest Shi’ite power, condemned the attack.

“We hope Taliban leaders take decisive action against these wicked terrorist incidents,” it said in a tweet.

Taliban special forces arrived to secure the site and an appeal went out to residents to donate blood for the wounded.

The blast, coming so soon after the Kunduz attack, underlined the increasingly uncertain security in Afghanistan as the Taliban grapple with an escalating economic and humanitarian crisis that threatens millions with hunger.

The local affiliate of Islamic State, known as Islamic State Khorasan after an ancient name for the region covering Afghanistan, has stepped up attacks following the Taliban victory over the Western-backed government in Kabul in August.

Taliban officials have played down the threat from Islamic State, and dismissed suggestions they may accept U.S. help to fight the group. But the repeated attacks have tarnished their claim to have brought peace to Afghanistan after four decades of war.

The fact that the Shi’ite minority has again been targeted may also inflame tensions among ethnic and sectarian groups in the largely Sunni country. Most Shi’ites in Afghanistan belong to the Hazara ethnic group of Persian speakers, who have complained of persecution under the mainly Pashtun-speaking Taliban in the past.

By Gibran Naiyyar Peshimam.

(Additional reporting by Jibran Ahmad, Islamabad bureau; Writing by James Mackenzie Editing by John Stonestreet, Robert Birsel, Peter Graff).