Police are searching for a 12-year-old girl from Crawley who went missing after leaving an address in Portslade.
Starlene Dempsey is believed to be with her friend Chloe James, 15, of Seaford. Both girls were last seen on Sunday (April 27).
Officers have extended their search to London.
Detective Inspector Lee Horner said: “Both girls have gone missing before and from previous experience, we believe that they may be putting themselves at serious risk due to the people they are likely to associate with.
“We have information that they are thought to be in the Newham or Tower Hamlets area of London and two Sussex officers have travelled to the capital to link with colleagues in the Metropolitan Police who are assisting with the search.
“I would urge the girls or anyone who knows where they are to contact police now on 101 quoting serial 1385 of 27/04. If they are in danger or need medical assistance, please dial 999 immediately.”
Sussex police officers have extended their search for two missing young girls to London amid mounting worries for their welfare.
Fifteen-year-old Chloe James was dropped at the railway station in her home town in Seaford on Sunday (April 27) around midday and had a return ticket to Lewes where she was expected to see a friend. A police officer did speak to her on Sunday and she did say she would be returning home, but has so far failed to do so.
She is thought to be in the company of her friend, Starlene Dempsey, 12, who went missing after leaving an address in Portslade on Sunday and who has not returned to her home in Crawley.