A 17-year-old with links to Croydon was reported missing a day after her birthday.
Michelle Brewer, of Plaistow Lane, Bromley, was last seen leaving home at 7pm on August 12.
Michelle is described as a white, with shoulder-length dark brown hair and is around 5ft 6 tall. She was last seen wearing a black jumper, dark jeans, grey Nike trainers and carrying a yellow and black JD Sports bag.
Michelle has been reported previously, the Met has said, but police are concerned for her welfare and are keen to hear from anyone who may have seen her.
Anyone with information should call police in Bromley on 101 or contact the Missing People Charity on 116 000.