Update: Police said Peter has been found safe and well after a helicopter assisted search in the city.
People in Lincoln are being asked to look out for a missing man last seen in the Calder Road area.
Peter Warren, 70, was reported missing on Wednesday, May 15.
Police released an appeal to trace him.
Anyone who thinks they may have seen him should call Lincolnshire Police on 101, quoting incident 257 of May 15.