The Islamic State in Iraq and Syria (Isis) claimed responsibility for the killing of a Hindu monastery worker in Bangladesh, according to a monitoring service tracking militant activity online.

The 60-year-old worker was attacked by unidentified assailants in the north-western district of Pabna early on Friday morning.

The elderly man was found lying in a pool of blood. Police said no one saw the attackers as the incident happened early in the morning.

This incident was the third killing of a member of religious minorities in Bangladesh that the group has claimed responsibility for in the past week.

The SITE Intelligence group said the jihadist outfit claimed the attack. Earlier, an elderly Hindu priest and a Christian shopkeeper were hacked to death and both the killings were claimed by Isis.

Since last February, militants have killed more than 30 people in Bangladesh, including members of religious minorities, liberal bloggers and academics.

According to SITE, Isis has claimed responsibility for 21 of the attacks and Al-Qaeda has claimed most of the other attacks.

However, Prime Minister Sheikh Hasina's government has rejected the Isis and Al-Qaeda claims and blamed homegrown terrorists for the attacks.

Bangladesh is mainly a Muslim country with Hindus and Christians making up about 10 percent of its 160 million population.