There was tight security at an abandoned quarry near Yuen Long yesterday when experts started to move a 10-tonne haul of fireworks.
Electronic devices were not allowed within 25 metres and detectives were told to remove their guns.
The haul, found on Tuesday night, was enough to stage a half-hour display.
Nine tonnes of explosives were used in the handover firework display. A fireworks show of similar scale is expected at the end of the month to mark the Year of Tiger.
Bomb disposal experts said the haul, seized in Au Tau, Yuen Long, was powerful enough to shake Pok Oi Hospital about 500 metres away if set alight.
The entrance to the Tai Shu Ha quarry was sealed, and police had kept watch since the fireworks were put there.
An investigator said: 'We cannot be too careful. The haul is very big.' Investigators believed the fireworks were intended for illegal sale to New Territories villagers for the Lunar New Year.