http://img139.imageshack.us/img139/1...mattackme7.jpg Detectives are looking for a black woman who spat at a commuter and threatened to throw her onto railway tracks .  The Polish woman victim was subjected to a physical and verbal assault at Streatham station after asking the suspect when the next train was due.   Police are looking for the , pictured left , African-Caribbean woman of slim build over the attack at 1450 BST on 6 March.   Detectives believe the assault may have been witnessed by other commuters.   This incident was particularly nasty in that the suspect spat at the victim and then slapped her before threatening to throw her onto the tracks, DC Sayeed said.  Given the time of the day police believe other people may have witnessed the assault and we would appeal for anyone who saw the incident to contact police.