Organizers of a show billed as a "silent" fireworks display northwest of London apologized Monday after parents complained the explosions made a lot of noise, frightening young children.

Advertisements claimed the Birmingham Botanical Gardens show would feature "no bangers or loud noises," perfect for kids, the BBC reports.

But some parents complained on social media that the blasts Thursday night were "very loud," and sounded "like regular fireworks."

The CEO and curator of the Gardens, James Wheeler, apologized and said refunds would be handed out, according to the Birmingham Mail.

Wheeler added, "We were advised these illuminations would give off a minimal amount of sound, with many being deemed as silent. We are sorry they were not as advertised and we will not be staging this event with this provider again."