Images of a man wanted in connection with a series of phone jackings have been released as transport police warn passengers to be on their guard.
British Transport Police are looking for the man after five separate attacks on trains between Selhurst and Balham in two weeks.
In the first offence a woman was approached from behind at 1.30pm at Balham station and had her phone snatched from her hand.
The following day at 2.50pm again at Balham, a man boarded a train and sat by a woman with her phone in her hand.
At Selhurst station he suddenly grabbed her purse and phone and left the station.
The next incident, on August 25, another woman, travelling towards Streatham Common, had her phone snatched from her hand as she was in mid-conversation.
Two days later a man using his phone while the train was waiting at Selhurst station was attacked and had his mobile wrenched from his hand.
He chased the man who dropped the phone and the victim was able to recover it.
Only the next day, on Tuesday August 28, a woman travelling to Streatham with her phone and Oyster Card in her lap was targeted.
The man snatched the items and left the train. The victim believes he took another train at Norbury.
Using CCTV police have identified a man they want to talk to over these thefts.
Police are asking passengers to be wary and keep valuables out of sight and to make a note of their mobile IMEI number which will allow a phone operator to block it in case of theft.
To find out your IMEI no. type *#06# into your phone.
Anyone wo knows this man, or has details regarding the crimes, should call the transport police on 0800 40 50 40 quoting number reference is B6/LSA of 30/08/12