Families were forced to flee an Australian cinema when a trailer for a horror film dubbed “the year’s scariest film” was accidentally shown before a school holidays showing of Peter Rabbit.

WAtoday reports that the incident occurred an Anzac Day holiday screening of the Beatrix Potter adaptation at Event Cinemas in Innaloo, Perth. As audience members settled down for the film, a trailer for Hereditary began to play. The film, which stars Toni Colette, has received an MA15+ rating in Australia for “themes of strong horror”. Its trailer features a number of unsettling scenes, including one in which a child appears to cut the head off a dead pigeon with a pair of scissors.

“It was dreadful. Very quickly you could tell this was not a kid’s film,” an audience member told the newspaper. “Parents were yelling at the projectionist to stop, covering their kids’ eyes and ears. Some parents fled the cinema with their kids in tow.”

The cinema eventually switched off the screen, and later offered audience members complimentary tickets as a gesture of goodwill. A spokesperson for Event Cinema’s parent company, Event Hospitality and Entertainment, said that the issue was being “investigated internally to ensure situations like this do not occur again”.

This is far from the first time a screening for a family-friendly film has been preceded by an unsuitable trailer. In 2012, a cinema in south London accidentally screened trailers for horror film The Devil Inside and Ghost Rider: Spirit of Vengeance, which stars a flaming skeleton on a motorbike, ahead of a showing of Puss in Boots, while in 2013 a teaser for Lars von Trier’s sexually explicit arthouse drama Nymphomaniac appeared in advance of a screening of Frozen in Florida. Three years later, the trailer for profane animated comedy Sausage Party was shown before a California cinema’s screening of Pixar’s Finding Dory.