Mariama Kallon, 13, was reported missing last Thursday, February 9, after she attended school in Bermondsey but did not return to her home in Southwark.
She was last seen wearing a black top and pink trousers.
Police are appealing for help to find a 13-year-old girl who has been missing for more than a week.
It is not the first time the teenager has gone missing, the force said. Sky reported.
Mariama previously stayed away from home overnight and went to school the next day as normal – however, her school was not open last Friday and this week is half-term.
Detectives say there have been two sightings of her over the period she has been missing.
The teenager was wearing different clothing both times – a black top and blue trousers on Friday and a black top with pink trousers and a heavy scarf on Monday.
She was first spotted on the morning of Friday February 10 in the area of Markham Street, Southwark and then on the afternoon of Monday February 13 in Riddons Road, Lewisham.
Detective Sergeant Dick Nation, from the Central South Missing Persons Unit, said: ‘We believe Mariama is avoiding going home and as a result of her school being closed, has been out of contact for much longer than normal.
‘There is no evidence that she has come to harm or is at any imminent risk of harm, but the duration of her disappearance is a cause for concern.
‘She is 13 and we do not know where she is staying or who she is staying with. We do not know if she is in the company of any responsible adults.
‘If you have seen Mariama or have any information on her whereabouts, please contact us.’
He added: ‘I would also like to send a message to Mariama if she is reading this.
‘We know there are many reasons why a child may avoid going home. You are not in any trouble but we need to make sure you are safe.
‘We are here to talk to you and to help you with whatever problems you may be having.
