Police say the suspect has been arrested at the scene of the blast, which happened after midday prayers.
At least six people have been wounded in a grenade blast at a mosque in a densely populated area of the Afghan capital, Kabul, police said, minutes after worshippers offered midday prayers.
Attacks on public targets have largely diminished since the Taliban seized power in August last year, but ISIL (ISIS) affiliates continue to operate in parts of the country.
“We had finished the prayers and were heading out of the mosque when the blast occurred,” worshipper Mohammed Yasin told the AFP news agency.
Kabul police spokesman Khalid Zadran told AFP a grenade was thrown into the Pul-e-Khisti mosque and a suspect was arrested at the scene. The mosque is located in a densely populated area of Kabul and is surrounded by busy shops and markets.
No group has claimed responsibility, but the Islamic State of Khorasan Province (ISKP, ISIS-K) group has carried out recent attacks in Kabul and other cities.
The ISKP claimed the attack on a military hospital in Kabul in November which left 19 dead. The group also claimed the October suicide attack on a Shia mosque in Kandahar which in at least 60 people were killed.
Taliban officials insist their forces have defeated the group, but analysts say the ISKP is a key security challenge to the new rulers of Afghanistan.
In February, the United States offered up to $10m for information leading to the location or identification of Sanaullah Ghafari, the leader of ISKP, the Afghanistan affiliate of ISIL.
In a separate attack on Sunday, at least one person was killed and 59 others wounded in an explosion at the country’s largest money changing market, Sarai Shahzada – not far from the attacked mosque.