The Calcutta High Court on Thursday ordered an NIA investigation into the violence in Shibpur in Howrah district during Ram Navami celebrations.

Hearing a public interest litigation (PIL) filed by Leader of Opposition Suvendu Adhikari, a division bench presided by Acting Chief Justice TS Sivagnanam directed for the transfer of investigation to the National Investigation Agency (NIA) from the West Bengal Police as reported by PTI.

In the PIL, Adhikari sought an NIA probe into the violence, during which it was alleged that bombs exploded.

The court directed the state police to transfer all records and CCTV footage relating to the matter to the central government within two weeks.

The Centre was directed to send the documents to the NIA thereafter.

The Calcutta High Court had previously observed that a probe by a central agency is required if an unconnected third party is found to be trying to take advantage of such unrest and joins a clash between two groups.

"If that (third) group is involved, then it requires an investigation by a central agency. It is very difficult for a state police to find as to who has come in to take advantage," a division bench presided by Acting Chief Justice T S Sivagnanam said.

There must be a mechanism to put an end to violence during religious functions and to instil fear in those indulging in such acts, the court said.

Additional Solicitor General Ashok Chakraborti, who represented the NIA, submitted that according to the petitioners, there were several blasts at Shibpur and Rishra during the Ramnavami procession and after. Once there is an occurrence of an explosion an NIA investigation is called for as per law.

A preliminary finding of the CID suggested that the Ram Navami procession that was moving down GT Road in Howrah's Shibpur made an unscheduled stop for almost over 25 minutes in front of a gated complex a few metres ahead of the Shibpur police station.

The spot where the procession of several hundreds brandishing swords and daggers and carrying saffron flags stopped is known for its mixed demography in Kazipara.

A source said CCTV footage revealed that the procession stopped near Panchsheel Apartment, a gated complex on GT Road that stands opposite the locality that is predominantly inhabited by minorities.

Located close to the Shibpur police station, several residents of the apartment complex were witness to the violence, police have learnt.

Footage available with the police has also shown some youths trying to enter the Panchsheel complex and throwing plastic chairs when others managed to close the entrance gate.