AN investigation was under way last night after nine people at a horse show were injured when a burger van exploded into a ball of fire.

The National Pony Society event in Harrogate was thrown into disarray after the blast late yesterday morning.

A fleet of three ambulances were scrambled after the emergency call and four people were treated at the scene by paramedics.

Another five people were taken to Harrogate District Hospital for treatment – although their injuries were said to be minor scalds and burns The explosion took place just after 11.30am at the Great Yorkshire Showground and local fire crews reached the scene within minutes.

As they arrived at the scene they found the burger van well alight, but they were able to quickly extinguish the flames using two hose reel jets and four sets of breathing apparatus.

It is believed the explosion was caused by a propane gas cylinder exploding and fire crews remained at the scene until mid afternoon, cooling down two 19kg propane cylinders that had been close to the flames to prevent the risk of a further blast.

Some visitors to the show reported seeing two explosions from the van and one witness said the people working in the fast-food outlet had been injured in the blaze, along with some people waiting in the queue for food.

“People were saying something had exploded and a fire ball came out of it,” said the witness.

“I heard a bang and when I looked across, we saw the van was on fire.

“Apparently, a few people have been quite badly burned and were with paramedics. I think two people working in there were quite badly burned.”

Show secretary Jane Burnell said the event was held up for about 45 minutes in the wake of the explosion but then continued without further incident.

“This is a competitive show rather than a big public one, so there was no big crowd,”

she said.

“I would say 99 per cent of the people that were here were either competing or connected to those who were.”

She said a few people had suffered minor injuries or shock, but details of what caused the incident were still unclear.