Shyamanada Das, 55, was picking flowers for his prayers shortly after 5 a.m, was hacked to death by Islamist in Bangaladesh

DHAKA, Bangladesh — Attackers wielding machetes killed a Hindu priest in Bangladesh on Friday morning, the fourth Hindu to be targeted during the past month in more than three years of similar killings by Islamist militants in this Muslim-majority country.

Islamic State militants claimed responsibility for the death in a report by the group’s Amaq News Agency, according to the SITE Intelligence Group, which monitors extremist activity online. Responsibility for many other attacks had been claimed either by the Islamic State or a branch of Al Qaeda, but the Bangladeshi government has persistently denied the presence of such extremist networks in the country.

The police suspected the involvement of the student wing of the country’s largest religious political party, Jamaat-e-Islami, because a man arrested in connection with a similar killing of a Hindu priest in the same district three weeks ago claimed membership in that group, said Gopinath Kanjilal, an assistant superintendent of the police for the Jhenaidah district in southwestern Bangladesh, where the attack occurred.

A Jamaat leader in the region, Shah Alam, interviewed by phone, denied that the group’s student wing was responsible for the killings.

The priest killed on Friday, Shyamanada Das, 55, was picking flowers for his prayers shortly after 5 a.m. when three men wearing helmets pulled up on a motorcycle, Mr. Kanjilal said. Two of the men jumped off and attacked the priest with machetes, killing him with blows mostly to the back of his neck, Mr. Kanjilal said.

More than 40 people have been killed in Bangladesh in a series of attacks that began in early 2013. The attacks initially targeted bloggers but then expanded to include foreigners, gay activists and members of religious minorities. In an effort to forestall further violence, the government announced a crackdown in early June and has arrested more than 11,000 people, 194 of them said to be linked to militant networks.

Kajal Debnath, a presidium member of the Bangladesh Hindu Buddhist Christian Unity Council, said that Hindus, particularly in rural villages, are terrified and call his organization daily wondering if they will survive the latest outbreak of killings. They have been victims of oppression in Bangladesh for decades and do not know why they have suddenly become the “prime target of a series of similar killings,” he said.

“We are really feeling very helpless,” he said.