Less than a week after a teenager had to have part of his liver removed following a horrific stabbing incident on a train platform, another man has fallen victim to a frenzied knife attack at a Croydon station.

Last Tuesday a man was pushed on to the tracks at Norbury station and repeatedly stabbed in the back.

Police said he had been involved in a fight on the platform edge at around 7.40pm and was pushed on to the tracks.

His attacker followed him and continued stabbing him before fleeing the scene.

The victim, a 40-year-old Norbury resident, suffered a collapsed lung and was taken to Mayday Hospital. He has since been released and is recovering at home.

British Transport Police (BTP) are searching for the attacker and have released a CCTV image of a man. He is described as black, aged in his 30s, with a small goatee beard, braided hair and of large build.

"We have had a good response from witnesses at the scene," said Detective Sergeant Darren Stenning who is investigating the case for Croydon BTP.

He added that the public "shouldn't worry" and said: "It is a serious crime but it is not a crime that appears on the railway every day.

"But when a person's life is threatened it is taken very seriously and patrols have been heightened in the area to reassure the public."

The Norbury attack occurred less than a week after a 19-year-old man was approached by a gang of six youths and stabbed at Thornton Heath train station in Brigstock Road.

He sustained a six-inch long stab wound and was rushed to St George's Hospital in Tooting where he underwent emergency surgery and had part of his liver removed.

The shocking attacks come after a high-profile knife amnesty, which despite its good intentions appears to have had little impact.

In February statistics released by the London Assembly's transport committee put the borough's main station, East Croydon, at the top of the table for crimes reported in 2004-2005.

East Croydon had 328 crimes in the 12 months to April last year - almost one a day. The station was said to be worse than Europe's busiest station, Clapham Junction, which came second with 273 crimes.

Croydon police rubbished the crime statistics and high-ranking officers claimed the statistics were out of date.

And Southern, the company which manages East Croydon station, said that over the last few years, 24-hour CCTV, help-points and a round-the-clock staff presence have been implemented.

Speaking about the latest station attacks Inspector Jack Ioannou of Croydon British Transport Police said: "These were isolated incidents. Our statistics show that these types of crimes are rare and it is very coincidental that two have happened."

He added that his force had extended its Operation Shield - where a metal detector is placed in the entrance of train stations - to smaller stations in the borough.

"This is going to have an impact on knife crime," he said, adding: "We have crime hot spots and neither of these stations is one of our hot spots. These are two rare crimes on the rail network and we are robustly investigating them.

"We will continue to work with our partners to make sure the stations are safe and there is no evidence to substantiate that this is going to happen again."

If you have any information about the two knife attacks call 020 7391 5275 or Crimestoppers anonymously on 0800 555 111.