At least five civilians were killed in a bomb blast outside a Kabul mosque on Sunday, a Taliban official said.
It was the deadliest attack in the Afghan capital since US forces left at the end of August.
There was no immediate claim of responsibility, but suspicion fell on ISIS extremists who have increased attacks on the Taliban in recent weeks, particularly in their eastern Afghanistan stronghold of Kandahar.
A roadside bomb went off at the gate of the sprawling Eid Gah Mosque in Kabul as a memorial service was being held for the mother of chief Taliban spokesman Zabihullah Mujahid.
Five people were killed, said Qari Khosti, the spokesman for the Interior Ministry.
The explosion showed the growing challenges the Taliban face weeks after they took control of Afghanistan in a rapid campaign that culminated in their takeover of Kabul on August 15.
During their 20-year insurgency, the Taliban frequently carried out bombing and shooting attacks, but are now faced with trying to contain rival militants using the same methods.
The growing security challenges come at a time of economic meltdown, as the Taliban struggle to run the country without the huge foreign aid given to US-backed government they toppled.
Three suspects were arrested in Sunday’s explosion in Kabul, said Bilal Karimi, a Taliban spokesman. He said Taliban fighters were not harmed.
Mohammad Israil, a Kabul resident, said he heard “a loud sound” and saw people running away.
An Italian-funded emergency hospital in Kabul tweeted that it had admitted four people who were wounded in the blast.
The area around the mosque was cordoned off by the Taliban, who maintained a heavy security presence.
Later in the afternoon the site was cleared. The only sign of the blast was slight damage to the ornamental arch by the entrance gate.
ISIS maintains a strong presence in the eastern province of Nangarhar, where it has claimed responsibility for several killings in the provincial capital of Jalalabad.
In late August, an ISIS suicide bomber attacked during American evacuations at Kabul’s international airport.
The blast killed 169 Afghans and 13 US service members, and was one of the deadliest attacks in the country in years.
Attacks in Kabul have so far been rare, but in recent weeks ISIS has shown signs that it is expanding its presence beyond the east and closer toward the capital.
On Friday, Taliban militants raided an ISIS hideout north of Kabul in Parwan province after a roadside bomb wounded four fighters in the area.