Computer-controlled road signs in the US warned that zombies were ahead after being hacked by pranksters, it has been revealed.
The warning notices in Austin, Texas had informed drivers that they were approaching a construction area before the jokers changed the message.
While some local residents appreciated the stunt, authorities have admitted that they were not amused.
Student Jane Shin, who was with friends when she saw the signs, told KXAN-TV: "I thought it was pretty funny. We wondered who did it."
Sara Hartley, a spokeswoman for the public works department, confirmed that the culprits had cut through a padlock on one sign to gain access to the computer system, which was then hacked.
"Even though this may seem amusing to a lot of people, this is really serious, and it is a crime," she explained. "And you can be indicted for it, and we want to make sure our traffic on the roadways stays safe."