The police say the man appeared to be mentally unstable.

Highlights Initially the women didn't protest but then one woman decided to act

The woman's courage encouraged others in the compartment to protest

The railway staff caught the man however he later managed to flee

A man who was masturbating on a platform at a railway station in West Bengal was shown live on Facebook by a woman inside a train. The train was about to leave the Bandel station when the man began to masturbate right outside the women's compartment. The man escaped after the railways staff took notice.

The incident took place around 1.15 pm today when the Howrah-bound local arrived at the Bandel station. The man in his mid-50s made obscene gestures as some women looked away.

Initially, the women didn't protest as the train was about to leave the platform, but then a woman in her 20s decided to take charge. She pulled out her mobile phone and went live on Facebook.

"These days everyone needs proof, so we decided to do a Facebook live. Let him do whatever he wants," the woman says in the video.

Her courage encouraged others in the compartment to protest. Some of them inform the staff before getting back to the train.

The woman pulled out her mobile phone and went live on Facebook.

He was doing all this in full public display, and he was standing in front of railway police office. When the staff saw me making a video, they sprang into action and got him. But the man managed to escape. The video ends at this point," the woman told NDTV.

The police said that he boarded the train and fled.

"He appeared to be mentally unstable. We have informed the Burdwan GRP, but he is untraceable," said a Railway police official at Bandel.

Earlier in May, a man was caught masturbating on a bus in Kolkata. The man, a hawker, was later arrested after the woman posted the video on Facebook and approached the Kolkata Police on their official Facebook page. The police had described him as a "man with a diseased mind".