Police have issued a warning to home-owners in the Dungannon area over fears that strange chalk marks appearing on houses might be audacious thieves targeting the rich and vulnerable.
Residents are concerned that the marks might be a series of coded symbols which criminals are using to tip off other criminals.
Dungannon and South Tyrone police have posted warnings on social media, alerting the public to the dangers.
They have asked the public to send them photographs of the markings, which have appeared on exterior walls, adjoining roads and pavements.
“We’ve been receiving reports from people who are concerned about chalk marks on their property”, said local police.
“To date, we have no evidence to connect these markings with criminal activity. However, please do let us know about your concerns. If you notice chalk markings on your property, take a photograph, then remove them. Phone us on 101 to report it. Also let us know if you see any vehicles that you believe are acting suspiciously.”