Four people have been arrested in the eastern Indian state of Jharkhand for allegedly burning to death a woman and her 10-month-old son on suspicion of practising witchcraft earlier this week.

The woman's husband, who was also attacked, suffered severe burns and is in hospital.

Police say they are searching for more people who may be involved. The accused are in custody and haven't commented publicly yet.

According to the National Crime Records Bureau, more than 2,500 people, mostly women, were killed in India on suspicion of witchcraft between 2000 and 2016.

Tuesday's murder of Jyoti Sinku and her son occurred months after five members of a family in neighbouring Bihar state were brutally killed and allegedly burned alive on accusations of practising witchcraft.