Police are advising residents to to lock their doors in the evening after a number of burglaries in Lincoln this week.
A thief entered a flat in Lindum Terrace on Tuesday afternoon through an unlocked door, stealing a passport, a laptop and electronics.
An offender also broke into a house in Bernard Street through the front door at around 4pm on Tuesday and stole two laptops and 15 bottles of wine.
Burglars are operating in residential areas in Lincoln and officers are asking residents to be vigilant.
They are advising people to lock their doors in the evening, even if they are at home, to prevent sneak-in thieves.
They are also asking people to report anyone acting suspiciously in their area to the police as soon as possible.
Call Lincolnshire Police with information on 101, or call independent charity Crimestoppers anonymously on 0800 555 111.