MUMBAI: A man barged into the ladies compartment of a Central Railway local on Sunday night, assaulting two commuters and threatening a third with a weapon. The women raised an alarm and got him caught at Sion station with the help of bystanders on the platform. The Railway Protection Force (RPF) recovered a knife from him.Around 8.32 pm, a 21-year-old beautician, Nasreen (name changed), was waiting to board a train with her friend at Matunga station. They noticed a man humming film songs, looking in their direction. As a Down train arrived, the man followed Nasreen and other commuters into the ladies coach."He stood at one of the doors and started singing songs loudly this time. He also exposed himself and we were all disgusted. An elderly woman asked him to stand properly and not behave like a madman. He lost his cool and slapped her. Another elderly woman rushed to her aid and confronted him. But he slapped her as well," Nasreen said.The man now turned his attention towards a commuter who was silently playing games on her cellphone. "He suddenly snatched her cellphone and flung it out of the train. I cried out in alarm that all of us needed to come together and apprehend this man without getting scared. He headed directly towards me and pointed a knife at my throat," Nasreen added.By this time, several women in the coach had started to scream for help. As the train stopped at Sion station, some women commuters alighted and sought help from people on the platform. "The crowd on the platform gestured at me to keep the offender busy in conversation so he wouldn't know that they were coming for him. I kept begging him to let me go. Bystanders then pulled him out and thrashed him. I dialled the railway security helpline '182' and RPF personnel arrived soon after," Nasreen said.The man was hauled to the RPF outpost. The woman whose phone he had flung and another whom he had slapped accompanied the RPF to press charges against him. Nasreen left her contact details with the RPF as her family was waiting for her at home. A case will be registered against him, officials said.