ISLAMABAD (AP) — A gunman stormed a mosque in western Afghanistan, opening fire and killing six people as they were praying, a Taliban official said Tuesday.

Local media reports and a former president of Afghanistan said the mosque was targeted because it was a place of worship for the country’s Shiite Muslim minority.

The attack happened on Monday night in the district of Guzara in Herat province, said Abdul Mateen Qani, a spokesman for the Taliban Interior Ministry. He said in a post on the social media platform X that an investigation was underway.

No one immediately claimed responsibility for the attack, which also wounded another worshipper while the attacker fled. Local media reported that the mosque’s imam was among those killed.

“I strongly condemn the attack on the Imam Zaman Mosque,” former Afghan President Hamid Karzai said on X. “I consider this terrorist act against all religious and human standards.”