The bomb targeted the sprawling Eidgah Mosque in Kabul, where a memorial service was being held for the mother of Taliban spokesman Zabihullah Mujahid, who later tweeted the attack had claimed civilian lives.
Emergency NGO, an Italian-funded hospital in Kabul, tweeted it had received four people wounded in the blast.
Sunday’s bombing was the second major attack in the Afghan capital since the Taliban takeover. An August 26 attack on the Kabul airport, which killed 182 people, was claimed by the IS-K, the Islamic State group’s Khorasan branch.
No one immediately claimed responsibility for Sunday’s attack.
The bombing at an iconic Kabul mosque raised questions over whether the Taliban can maintain security amid rising threats from the IS-K group.
Under the terms of the US withdrawal deal, the Taliban promised to maintain security in Afghanistan and ensure the country did not turn into a haven for jihadist groups.