A riding school said an unexpected fireworks display nearby caused chaos at its stables when its frightened horses escaped.
Park Lane Stables, Teddington, claimed the National Physical Laboratory (NPL) did not give any prior warning about its staff ball.
Horses scared by the loud bangs broke free but workers at the family-run stables rounded them up before they reached the road. Residents in Queen’s Road also said they were shaken by sudden “explosions” that woke their children and terrified their pets on Saturday, June 16.
The NPL said it warned its immediate neighbours about the event but did not expect the fireworks to disturb people living further away.
Natalie O'Rourke, of Park Lane Stables, said it was not able to use some of its horses for lessons the following day because they were too nervous.
She said: “It was chaos here really, if we’d known we’d have taken them away to paddocks. They didn’t get out onto road but got out of the stables and were running around distressed.
“Normally they let us know, we’ve got system in place and we can deal with it. We had no idea it was going ahead.”
Neighbour Clarys Williams, 62, complained to the NPL about the fireworks.
She said: “These weren’t just fireworks, they were like pyrotechnics.
“I must have got home at about 11.10pm, [my cat] Sam was cowering behind the sofa and wouldn’t come out for two hours.”
She added: “On new years’ eve you expect fireworks at midnight, but you’re prepared.”
Stephen Hyett, 63, added: “We had some friends around for dinner and at about 10.50pm we heard an almighty boom. We had no idea what it was - we thought it was a bomb.”
A spokesman for the NPL said: “I can confirm that there was a fireworks display as part of the NPL staff ball on Saturday, June 16.
“A couple of our neighbours have been in touch regarding the display and we are responding to them directly.
“We did inform residents in the immediate vicinity of the National Physical Laboratory, but clearly the fireworks could be heard further away than we had anticipated.”