A man was beaten up by a mob in North Kolkata on suspicion of him being a child-lifter, police said on Saturday.
A police officer was also heckled when he tried to rescue the youth late on Friday evening.
After being informed, personnel from Phoolbagan police station reached the spot and rescued the victim.
A total of 17 people were arrested in connection with the incident, police said.
Locals alleged that the man was roaming in the area wearing a burqa and was "trying" to lift children from behind a shopping mall.
Chief Minister Mamata Banerjee had alleged on Friday that attempts were being made to disrupt peace in West Bengal, with "burqa-clad men" being sent to streets to create panic amid rumours of child lifting.
"We are investigating the matter. We are trying to collect CCTV footages recorded by cameras installed at the shopping mall," a senior officer of Kolkata Police said.
A case was registered in this connection and police personnel were posted in the locality, he said.
"The youth is a resident of Narkeldanga area. Rumours were being spread that the youth was beaten to death, but it is absolutely false. He is undergoing treatment in a hospital and is at the moment stable," the officer said.
The rumours were being spread to create confusion and foment trouble, he said.
A social monitoring cell was opened at the state secretariat on Saturday to keep a tab on rumours on child-lifters spread through social media, officials said.
Recently there have been a spurt in incidents of mob violence fuelled by rumours spread through social media and several people were injured in different parts of the state.
A mob attacked a woman suspecting her to be a child-lifter in Howrah a couple of days ago.
Similar incidents were reported from other districts as well since last year.
The chief minister Friday urged the people to go to the police and lodge complaint about such incidents.