At least five assailants opened fire Thursday on devotees during evening prayers at a Shiite mosque in northern Bangladesh, leaving one person dead and three others wounded, police said.

Bogra district police chief Mohammed Asaduzzaman said by phone that the attack occurred just after sunset Thursday at the mosque in Haripur village.

He said a mosque official in his 70s who led the prayers died from bullet injuries and the three others are being treated at a hospital.

No one immediately claimed responsibility for the attack.

Shiites are a minority in Sunni-majority Bangladesh, a Muslim-majority nation of 160 million people.

The country has been rocked this year by a series of attacks allegedly carried out by Islamist radical groups. Since February, four secular bloggers, a publisher and two foreigners — an Italian aid worker and a Japanese agriculture researcher — have been killed, raising concern that religious extremism is growing.

An Oct. 24 bomb attack on thousands of Shiite Muslims at an annual rally in Dhaka left a teenage boy dead and more than 100 others injured. The Islamic State group claimed responsibility, but authorities rejected the claim and blamed members of the banned local group Jumatul Mujahedeen Bangladesh.

Munirul Islam, a senior Detective Branch official, told reporters Thursday that police have arrested at least six members of the banned group in connection with the October attack.

The Islamic State group also claimed responsibility for the killings of the foreigners, but the government insists that IS has no organizational presence in the country.

The government of Prime Minister Sheikh Hasina accuses domestic Islamist groups along with the main opposition Bangladesh Nationalist Party and its main Islamist ally, the Jamaat-e-Islami party, of carrying out the attacks to destabilize the country for political gain.