BOISE, Idaho (AP) — The Ada County Highway District isn't taking credit for a construction sign that temporarily warned drivers of "zombies ahead" in downtown Boise.

KBOI-TV reports (http://bit.ly/1UnnisT) the electronic sign bore the message on Sunday, and highway district spokeswoman Nicole DuBois says the contractor is responsible for the content.

The contactor has not returned a request for comment. It's unclear who is responsible for the zombie message.

The sign now warns drivers to use alternate routes as night work continues in the area.