Police are hunting a suspect following two incidents of indecent behaviour on trains to Goodmayes and Shenfield.

British Transport Police have released CCTV images of a man wanted in connection with the incidents, which left two victims feeling “frightened and violated”.

On January 16, a 23-year-old woman on the 17.43 National Express Liverpool Street to Shenfield train, who was travelling alone, noticed a man standing very close behind her.

He began to touch her inappropriately and she was unable to move due to the number of people in the carriage.

She had to wait until a seat became available to move away from him.

He continued to stare at her until he left the train at Goodmayes and she contacted police later that evening.

The second incident occurred a week later, on January 23, when the man sat opposite a 15-year-old girl on the 08:57 Stratford to Goodmayes service.

The victim, who was travelling on her own to school, noticed him staring at her and he continued to do so even when she met his gaze. He then began touching himself indecently.

She left the train at Goodmayes and he followed her onto another train before she got off at Seven Kings.

She contacted police when she arrived at school.

Det Con Graeme Knox, the investigating officer, said: “Fortunately incidents of this nature are rare on the rail network however we are treating them very seriously.

“Both victims were left feeling frightened and violated, and intimidating behaviour of this nature is simply not acceptable.

“Women should be free and able to travel on the rail network at whatever time of day they choose without the fear of becoming a victim.” Anyone who recognises the man or who has information should call BTP on 0800 40 50 40 quoting reference B3/LNA of 09/02/2012 or call Crimestoppers anonymously on 0800 555 111.