The couple was allegedly thrashed by a group of passengers at the Dumdum metro station on Monday evening, following their public display of affection in a train compartment.
"No complaint has been lodged after the alleged incident. It came to the metro's notice only when a news report came out in a Bengali daily yesterday. We thoroughly checked the CCTV footage at Dumdum and found no clear evidence of any assault," metro railway general manager Ajay Vijayvargiya said at a press conference.
However, there was a "faint" image of a few persons having assembled at a site at 21:55 hours and the image of a few people exiting from a gate, he said, while replying to a question.
As the current metro coaches did not have CCTV cameras, there was no footage of what had actually happened inside the coach after the couple boarded the train at the Chandi Chowk station, Mr Vijayvargiya said.
"The new coaches, to be commissioned shortly, will have CCTV cameras," he said.
The footage and the initial findings of the Railway Police Force or RPF were shared with the Kolkata Police yesterday, he said, adding that a joint memorandum of some students' bodies was also forwarded to the city police.
He said there would be increased surveillance across the metro stations, every part of the platform would be monitored with the help of CCTV cameras and an RPF Special Squad, with one woman member, would be deployed at every station.
The squad would also keep a vigil inside the coaches, especially during the late evening hours, Mr Vijayvargiya said.
He urged all the commuters to conduct themselves in a manner that did not tarnish the city's image.
"Please do not create a situation, where the metro authorities will be constrained to take action as per statutory and legal provisions," Mr Vijayvargiya said.
According to media reports, a man hugging his female friend had raised eyebrows inside a train compartment on Monday evening. A few people had objected to it and an argument ensued. The mob had then allegedly heckled the couple, pushed them out of the train and beat them up.
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