Three administrators of two groups on the social media platform Facebook were arrested on Thursday for allegedly spreading rumours about a gang abducting children in Barasat, in North 24-Parganas.

The police crackdown comes a day after the rumours led to the assault of three persons at two places in Barasat on suspicion that they were child lifters.

The police said the arrested trio claimed innocence and that they were “genuinely” under the impression that “a child-lifting gang was active in Barasat”. The police also said that they had not bought their theory.

They have been booked under the Information Technology Act and under IPC sections related to mischief and causing breach of peace in society.

The police identified the three as Pritam Mistry, Sheikh Mijanur Rehman and Payal Talukdar. All three are from Barasat.

Mistry, 33, works for a private IT firm and is a part-time insurance agent. Payel is a freelance make-up artiste. Rehman’s profession could not be ascertained till late on Thursday evening.

The Barasat superintendent of police, Pratiksha Jharkhariya, said the three arrested had been actively spreading rumours through two groups on the social media platform that a gang of child traffickers was active in the area.

“These three were the administrators of the groups. They were posting contents, including video clips, that were used to spread rumours that a gang of child traffickers was active in Barasat and was kidnapping children. They were also taking down our comments, made from our official account, in the groups to stop the rumours,” Jharkhariya said.

According to the officer, the three told the police that they had been posting videos and uploading comments since the body of a Class V student was recovered from a dilapidated toilet in Kazipara in Barasat on Thursday.

“They told our officers that they believed that the boy had been abducted and killed. They wanted to do something about it. So they started posting various contents, including videos of a body being recovered, and spreading the rumour,” said Jharkhariya.

The police said many more social media handles are under the scanner. Many of them are being handled through “fake profiles”, the police said.

“We are not ruling out the fact that this could be part of organised rumour-mongering that sparked violence in the area and left three injured,” said an officer.

Police posts have been set up in front of every major school in Barasat and senior police officers were out on the streets on Thursday speaking to residents, particularly those who drop their children to school and pick them up. Pamphlets were also distributed requesting people not to fall for rumours and not spread them.

This is not the first time social media platforms are being misused to spread rumours resulting in violence.

Several instances have been reported of rumours of child lifting in Calcutta and on the fringes leading to violence. In many cases, the rumour-mongers were arrested. But many more escape prosecution and the crackdown gets lax after the rumours fizzle out.

“The biggest challenge is to stop people from forwarding unverified messages through WhatsApp, Facebook are other social media platforms,” said an IPS officer who was earlier in charge of the cybercrime cell of Kolkata Police.

“Some people deliberately spread fake and concocted news to create communal tension or create law and order problems.”

A senior police officer in Barasat said the rumours had started circulating after the Class V student was found dead. The child’s uncle, Enger Nabi, has been arrested on murder charges and is now in police custody, the officer said.

Eighteen people have been arrested for Wednesday’s mob assault that left two men and a woman injured.