A 10-year-old girl was found dead under mysterious circumstances at her home in Kolkata's New Alipore area, the police said on Sunday.
The girl was found lying unconscious on the floor of the bathroom by her mother on Saturday night, they said.
Her mother took her to the Baghajatin Hospital with the help of a neighbour and doctors there declared her brought dead, the police said.
Doctors told police there were faint thumb marks on the neck of the girl but they couldn't conclusively say if she was throttled, an officer said.
Police said they were investigating the circumstances leading to the death, and if there was any foul play.
Things would be clearer after post-mortem, the officer said, adding that no one has been arrested so far.
The girl lived with her mother in the house and her father died a few years ago, locals said.