Three motorcycle-borne attackers slit the throat of Ananta Gopal Ganguly, 70, while he was en route to the temple he served in the district of Jhenaidah, about 100 miles (161 km) west of Dhaka, the capital, police said. "They almost beheaded him before they fled the scene," said police official Hasan Hafizur Rahman.
The attack bore the hallmarks of previous killings by Islamist militants. The government banned more than one person riding pillion on a motorcycle on Monday a day after the wife of a prominent anti-terror security official was shot dead by three suspected militants on a motorbike.
Islamic State claimed responsibility for killing Ganguly, the US-based monitoring service SITE said, quoting the militant group's news agency.
Rahman dismissed the group's claim as "baseless", saying it had no organisational base in Bangladesh and domestic militants were responsible. A 60-year-old Christian grocer was also hacked to death after Sunday prayers in an attack claimed by Islamic State.
Bangladesh has not seen the sort of Islamist violence that has rocked Muslim Pakistan, or even the number of attacks that India has seen over the past decade or so.
Since February last year, militants have killed more than 30 people in Bangladesh, including members of religious minorities, liberal bloggers and academics.
Islamic State and al Qaeda have claimed responsibility for most of the killings, but the government denies either group has a presence in Bangladesh.
Last month, junior foreign minister Shahriar Alam told a news agency that Islamic State was trying to ride a wave of religious radicalisation by falsely claiming killings, and said there was enough evidence implicating domestic militant groups.
The government has launched a crackdown on militant groups who want to impose strict Islamic law in Bangladesh. At least eight militants have been killed in shootouts since November, including three yesterday, police said.
Analysts say a climate of intolerance in Bangladeshi politics has both motivated and provided cover for perpetrators of crimes of religious hatred.
The government blamed the growing violence on its political opponents linked to Islamist parties aiming to create chaos and
prevent war crimes trials from going ahead.
Tension has risen since Prime Minister Sheikh Hasina ordered Islamist leaders suspected of atrocities during the 1971 war of
independence from Pakistan to be put on trial for war crimes.
Hasina's rivals accuse her of settling political scores by hunting down members of the Jamaat-e-Islami, an ally of the main opposition group headed by former prime minister Khaleda Zia. The government denies these assertions. Hindus and Christians make up about 10 percent of Bangladesh's 160 million people.
Three motorcycle-borne attackers slit the throat of Ananta Gopal Ganguly, 70, while he was en route to the temple he served in the district of Jhenaidah, about 100 miles (161 km) west of Dhaka, the capital, police said.
"They almost beheaded him before they fled the scene," said police official Hasan Hafizur Rahman.