Unidentified bike-riding assailants shot and hacked a Hindu priest to death Tuesday in southwestern Bangladesh amid a spate of similar attacks allegedly by radical Islamist groups since last year.

Local police chief Hasan Hafizur Rahman said three men intercepted 70-year-old Anando Gopal Ganguly while riding his bicycle to a temple in Jhenaidah district. Rahman said the three men on a motorbike first shot Ganguly and then slashed him with sharp weapons before they fled the scene.

Police had no immediate clues about who was behind the latest killing but they suspected that Islamist militant groups could be behind as the pattern of the attack was similar to previous ones. No group has claimed responsibility.

The killing of Ganguly took place two days after suspected Islamist militants killed the wife of a police superintendent who led drives against militant groups and drug cartels in southeastern city of Chittagong.

Also on Sunday, unidentified assailants killed a Christian man inside his grocery shop and the Islamic State group claimed responsibility for the killing in northwestern Bangladesh.

Authorities in Muslim-majority Bangladesh say suspected Islamist militants have perpetrated a string of killings since last year. Victims have included atheist bloggers, publishers, teachers, activists, minority groups members and foreigners.

The Islamic State group has claimed responsibility for some of the attacks, according to SITE Intelligence Group, but authorities have denied that ISIS has a presence in the country. The government of Prime Minister Sheikh Hasina says homegrown groups are responsible for the attacks to create chaos in the country.