A passenger was punched several times on a train which went through Southampton last week.

Police have launched an investigation after the assault on board a Great Western Railway train.

The passenger was punched several times by a stranger, British Transport Police said.

The force has released CCTV images in connection with the incident that occurred on the Portsmouth Harbour to Cardiff Central service on Thursday, August 22.

It is understood that the train passed through Southampton Central Station and other stations in Hampshire. 

Sometime between 7.10pm and 7.30pm, police said that a passenger was punched several times by a stranger as the train travelled between Warminster and Trowbridge.

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Investigating officers have now released CCTV images in connection with the incident. 

A spokesperson for BTP said: "Officers would like to speak to the man pictured as they believe he may have information which could help with their investigation.

"Anyone with information is asked to contact BTP by texting 61016 or by calling 0800 40 50 40, quoting reference 649 of 22 August.

"Alternatively, you can contact Crimestoppers anonymously on 0800 555 111."