Put the phone down (expletive),” “Don’t kill any kids today” and “Slow the (expletive) down” were displayed on the signs, police said.

The city's transportation department is removing the vulgar signs, which resemble speed limit signs, from at least four locations. Police are investigating.

Boulder police are investigating after four signs with explicit messages were found affixed to speed limit signs around the city on Tuesday.

Crews from Boulder’s Transportation and Mobility Department worked to remove the unofficial and explicit signs across Boulder Tuesday morning that were posing as speed limit signs.