A mysterious crate labeled "Wild Animals" and blasting out lions' roars in a German town had locals running scared and animal lovers up in arms before it was revealed as an advertising stunt, police said on Tuesday, according to Reuters.

"The crate was right in the town centre, and people thought there were real lions inside," a spokesman for police in the south-western town of Darmstadt told Reuters, adding: "It was loud. A lot of people were really scared."

Police came to investigate after two women complained about the treatment of the animals apparently locked in the crate, the news agency said.

Gingerly approaching the crate, they ventured a look through a slit in its side but, instead of discovering caged beasts angrily stalking the container, they saw a promotional video for Land Rover vehicles intercut with shots of roaring lions, Reuters said.

A Land Rover spokeswoman told the news agency the campaign had been running for a few months and had so far proved a success.

"We've generally only had positive feedback on it so far," she told Reuters, adding: "We've never had this kind of response before."