Kent Police are concerned about two 16-year-old girls last seen on 23 March at their homes in Northfleet in Kent.
Natalie Kelly and Rosina Lee are believed to be travelling to London to meet men they may have met on the internet.
More top news
Russia has announced that it will expel 23 UK diplomats in a deepening rift over the poisoning of a Russian ex-spy and his daughter.
Scores of flights were cancelled and drivers were warned to take care as the "mini beast from the east" swept in.
Sergei Skripal, the ex-Russian spy who was the target of the attack, and his daughter Yulia, remain in a critical but stable condition.