A Greenhithe man has been arrested after it's believed he "punched" a child in a disturbing assault while on a train to Gravesend last night.

According to the British Transport Police, it's believed that both the man has been become irate and began threatening passengers just as the train left Charing Cross station at around 8:30pm on Thursday, July 25.

As his behaviour became more aggressive, he reportedly the punched the victim, who is believed to be around 12-years-old.

The 28-year-old suspect, who's from the Greenhithe area, was then removed from the train and arrested by BTP officers on suspicion of assault, being drunk and disorderl and affray.

He still remains in police custody as of 10:30am today.

Officers are now appealing for any witnesses to this horrific attack and are trying to trace the victim as their enquiries continue.

British Transport Police Sergeant Tom Gallagher said: "I would ask anyone who witnessed this man’s behaviour and the reported assault on the child to please get in touch with us as soon as they can today to provide an account.

"The train was extremely busy and we believe many people helped to restrain him at the time who have not yet spoken to police.

"In particular, I would like to urge the victim of the assault, or their parents, to come forward and assist us with our enquiries.

"As you’ll imagine we are very concerned about the impact this incident could have had on them and we’d like to check on their welfare as soon as possible."

Anyone with information can contact BTP by texting 61016 or calling 0800 40 50 40 quoting reference 635 of 25/07/19.