Six men have been arrested in Bhubaneswar, Odisha for killing a woman and her four children, including a 10-month-old baby, over suspicion that she was a witch who killed a girl, police said on Tuesday.

Angry villagers broke into the woman's home and hacked her and her children to death with farm tools before dumping their bodies in a well, said investigating officer Sushant Dash.

The six, including a local witch doctor, were charged with murder and other offences under Odisha's Prevention of Witch Hunting Act on Sunday.

"They have confessed that they committed the murders for witchcraft," a source said, adding that a complaint by the woman's husband, who was away on the day of the killings, prompted them to hunt for the suspects.

"Two or three more people might be arrested in the coming days."

The villagers blamed the woman for the illness and death of a 12-year-old girl after the witch doctor told them she had cast a spell on the child.

"It is a form of violence against women and strict law alone cannot stop such crimes, we need to educate them," said Anuradha Mohanty, head of the People's Cultural Centre, a local child and women's rights group.

According to the National Crime Records Bureau, there were 134 cases of murders linked to witch hunts in 2016, with Odisha recording the most incidents after neighbouring Jharkhand state.