Twins Harrison and Harper, aged 11, Lacie, 12 and Chelsea, who is 13, were last seen at their homes in York yesterday.
“They did not return home last night and we are now searching the city to find them,” said a spokesperson for North Yorkshire Police.
“We believe they could be together.
“We’re issuing their images and asking people to keep an eye out and report any possible sightings by calling 101 and selecting option 1.”
Anyone with information about the children’s whereabouts is asked to give the following reference number when contacting police: 12240047121.
