At least five gunmen opened fire Thursday on a Shiite mosque in northern Bangladesh, killing at least one person and injuring three others, according to media reports. The Islamic State group, also known as ISIS, reportedly claimed responsibility for the attack.

The incident took place in the Bogra district, about 120 miles north of Bangladesh's capital Dhaka, during evening prayers at the mosque. Mohammed Asaduzzaman, Bogra district police chief, reportedly said that the man who was killed was a mosque official in his 70s. Authorities said that at least 20 people were performing prayers at the time of the attack.

“We never saw this type of attack in any mosque in the history of Bangladesh,” Shamim Mohammad Afzal, director general of Bangladesh’s Islamic Foundation, said, according to the New York Times, adding that the nature and timing of the assault were especially alarming.

In a claim released via Twitter accounts linked to ISIS, the Sunni militant group said that “soldiers of the caliphate” had opened fire on worshippers with machine guns.

“With permission from Allah, operations will continue on the Rafidha Iranian interests in Bangladesh,” the statement said, using a term for Shiite Muslims, according to the SITE Intelligence Group, the Times reported.