Police have issued a CCTV image of a man wanted in connection with the robbery of a 14-year-old boy on a Metro train in Sunderland.
The incident happened between 10pm and 10.25pm on Tuesday, 4 April.
The boy boarded the Metro at Monument Metro station in Newcastle and a man got on at the same time and sat opposite him.
As the train arrived at Park Lane Metro station in Sunderland at about 10.20pm, the boy was looking at his phone.
The man stood up as if to leave the train, then pushed the boy and grabbed the phone from his hand.
The victim chased the thief and struggled with him by the train doors, but the suspect ran off with the phone.
Another passenger came to the assistance of the teenager, who was distressed, and took him home.
British Transport Police would like to speak to the man shown in the CCTV images, as they say he may have information which could help the investigation.
If you recognise him or have any other information, call 0800 40 50 40 or text 61016, quoting reference number 294 19/04/17.