Thames Valley Police are urging anyone who has information about the whereabouts of a couple of young runaways to contact them immediately.
Amy Dilworth, 15, and Kieran Sampson, 12, ran away from a care home in Burghfield, in West Berkshire. They were last seen at 9.20pm on Saturday (13 June) at Mortimer railway station and are believed to have caught a train to London.
Inspector Steve Warren, from Newbury police station, said: "I would like to appeal to anyone who has seen Amy or Kieran or anyone matching their description to speak to police.
"They are both young people who have been missing overnight and we are concerned for them.
"Amy and Kieran: if you see this appeal, please contact the police so that we can ensure you are safe."
Thames Valley Police describe Amy as white, 5ft 10in, with short brown hair and last seen wearing a grey hooded top, a red and blue checked shirt, and navy chinos.
Kieran is white, 5ft, has blond hair and was wearing blue jeans and a grey jacket with the word "London" in red lettering on it.
Any is thought to have strong links to the Dagenham and Romford areas of Essex as well as London.
Anyone with information about Amy and Kieran's whereabouts is asked to contact the 24-hour Thames Valley Police enquiry centre on 101 quoting URN 1502 13/6.