A number of civilians have been killed in a bomb explosion at a mosque in Afghanistan’s capital Kabul on Sunday, the Taliban have said. The bomb targeted the Eidgah Mosque, where prayers were being held for the mother of Taliban spokesman Zabihullah Mujahid, who later tweeted the attack had claimed civilian lives. Taliban fighters were not been harmed in the attack, with Taliban spokesman Bilal Karimi telling the Associated Press (AP) that those killed in the attack were civilians outside the mosque gate. He did not provide a figure for the number killed and said an investigation was ongoing.

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Emergency NGO, an Italian-funded hospital in Kabul, tweeted it had received four people wounded in the blast.

The Taliban have cordoned off the area around the mosque and stepped up security presence.

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The Taliban returned to power in Afghanistan in August two decades after their ouster by the United States-led invasion of the country following the 9/11 attacks. While no one has claimed Sunday’s mosque attack, the Islamic State (IS) Khorasan has been trying to its assert its presence in Afghanistan following the Taliban’s takeover of the country.

IS maintains a strong presence in the eastern province of Nangarhar and considers the Taliban an enemy. The group has claimed several attacks against the Taliban, including for a series of bomb attacks in the city of Jalalabad in eastern Afghanistan. At least eight people, including several Taliban fighters, were killed in the attacks on Sunday and Saturday

In signs of growing tensions between the two groups, the Taliban on Friday raided an IS hideout just north of Kabul in Parwan province after a roadside bomb wounded four Taliban fighters in the area.

The IS also claimed a rocket attack on Kabul airport on August 30, as US troops were racing to complete their withdrawal from Afghanistan.