A TV station in Montana had its regular broadcast interrupted after hackers broke into the emergency alert system and warned of a zombie apocalypse.

The Montana television network KRTV told its viewers that "bodies of the dead are rising from their graves and attacking the living" and said a civil authority had issued an emergency in several Montana counties.

As well as a message scrawled across the top of the screen, a voice over was aired on the televised broadcast which warned viewers: "Do not attempt to approach or apprehend these bodies as they are considered extremely dangerous."

The message encouraged viewers to keep watching the on-screen message for further updates about the upcoming zombie apocalypse.

The message, which was broadcast over an episode of The Steve Wilkos Show on teen infidelity, was quickly removed and KRTV issued an apology.

KRTV said on its website that someone hacked into the emergency alert system and announced the emergency.

It added: "This message did not originate from KRTV, and there is no emergency.

"Our engineers are investigating to determine what happened and if it affected other media outlets."

The Great Falls Tribune claims four people rang the police to see if the reports were true.

A video of the zombie news alert can be seen below: