Organisers of this year's War and Peace Show have apologised to residents after complaints about late-night noise.
The event is the largest military vehicle spectacular in the world
The five-day event is being held at the Hop Farm Country Park, in Paddock Wood, Kent, and is in its 25th year.
Complaints were made to Tonbridge and Malling council over a firework display on Tuesday night and the sounding of an air raid siren during the evening.
Event organiser Rex Cadman said he had sympathy with residents and exhibitors were asked not to make noise at night.
"We do our very best to try and stop things like that," he said.
Mr Cadman explained that the show had grown much larger in size over the years from the original two-day vehicle event.
"Now it's a far bigger event, and a lot of people come in and set up huge displays," he said.
He said the firework display, which took place at 2300 BST, had been a one-off event to launch the show.
An investigation into the incident is being carried out by environmental health officers.
The War and Peace Show is the largest military vehicle spectacular in the world, featuring displays of more than 3,500 tanks and military vehicles as well as live battle re-enactments.