At least 30 people were killed after a blast ripped through a mosque in Kabul on Friday, amid a string of similar attacks that have occurred throughout Ramadan.
The blast hit the Khalifa Sahib Mosque in the west of the capital in the early afternoon, said Besmullah Habib, deputy spokesman for the interior ministry.
He said the official confirmed death toll was 10, but a health source said hospitals had so far received at least 30 bodies.
Emergency Hospital in central Kabul said it was treating 21 patients wounded in the blast and two patients were dead on arrival. A nurse at another hospital, who declined to be identified, said it had received several wounded in critical condition.
The attack came as worshippers at the Sunni mosque gathered after Friday prayers for a congregation known as zikr — an act of religious remembrance practised by some Muslims but seen as heretical by some hardline Sunni groups.
Sayed Fazil Agha, the head of the mosque, said someone they believed was a suicide bomber joined them in the ceremony and detonated explosives.
“Black smoke rose and spread everywhere, dead bodies were everywhere,” he told Reuters and added that his nephews were among the dead.
“I myself survived, but lost my beloved ones,” he said.
“The blast was very loud, I thought my eardrums were cracked.”
It comes a day after two bombs on separate minibuses killed at least nine people in the northern city of Mazar-i-Sharif, many of them Shiite passengers heading home to break their fast.
A bomb at a Shiite mosque in the city a week earlier killed at least 12 worshippers and wounded scores more.
ISIS has claimed responsibility for several of the recent attacks.
The regional branch of ISIS in Sunni-majority Afghanistan has repeatedly made Shiites and minorities such as Sufis, who follow a mystical branch of Islam, targets.
ISIS is a Sunni Islamist group, like the Taliban, but the two are bitter rivals.
The biggest ideological difference is that the Taliban's main focus has been an Afghanistan free of foreign forces, whereas ISIS is looking to establish an Islamic caliphate stretching from Turkey to Pakistan and beyond.
Taliban officials insist their forces have defeated ISIS, but analysts say the group remains a major security challenge.