An unprovoked attack on a woman waiting for a train at Elephant & Castle station has prompted a public appeal for information from British Transport Police officers.
The attack took place while the victim, a woman in her thirties from Luton, was waiting on platform 1 on Wednesday 5 February at 6.20pm.
"As she waited the woman was approached by a man who asked her to sponsor him, but she declined," said Detective Constable Rachel Smith.
"Initially the man walked away, but then returned a few seconds later and assaulted her. Once again he walked away, only to return a few seconds later and repeat his attack.
"The victim was forced to leave the station because of the man's confrontational behaviour, and the man followed her before returning to the platform and boarding a train to Bedford."
Officers have viewed CCTV from the station and have selected a number of images of a man they believe will have information on the attack and will be able to assist with their enquiries.
DC Smith added: "This was a horrible attack which caused bruising and swelling to the victim's head as a result.
"British Transport Police takes violent assaults extremely seriously, and passengers and staff should not be forced to travel on the rail network in fear of being attacked.
"If you recognise the man pictured, or have any information which can help, I urge you to contact us."
Anyone with information should contact British Transport Police on 0800 405040 quoting LSA/B8 of 20/03/13. Alternatively contact the independent charity, Crimestoppers, on 0800 555 111.