A cyclist suffered life-threatening injuries when she was deliberately knocked off her bike by moped riders.
The woman, in her 20s, was attacked in Harrow Road, west London, when her bag was snatched which caused her to fall and hit her head.
Detectives have appealed for help to identify the woman who was taken to a west London hospital.
They have yet to identify the woman who is white, aged between 18 and 20, about 5ft 3ins, with dark brown hair.
She was wearing a silver ring with a blue stone on her left hand, and had been riding a purple Dawes mountain bike.
She has a Chinese symbol tattooed on her right hip about an inch in size.
Detective Inspector James Raphael, of Paddington CID, said officers do not know why the woman was targeted.
Describing the attack, he said: "She was cycling along Harrow Road when suspects on two mopeds approached from behind.
"One has grabbed her bag off her back. This has led to her falling off her bike and hitting her head."