Stagecoach has confirmed that an inquiry will take place into the dramatic bus fire in Marlborough High Street on Monday morning.

The driver leapt into action when the engine of the Stagecoach bus caught fire outside Lloyd's Bank at 8.30am. He was unable to put the blaze out using a fire extinguisher so rang the fire service.

There were no passengers on the bus at the time and nobody was injured as a result of the incident, although the driver was treated by paramedics for smoke inhalation at the scene.

The High Street was closed for almost three hours while the incident was dealt with.

Jayne Harper, who was walking through the High Street at the time, said: “It was like Armageddon, it’s not the kind of thing you expect to see before your morning coffee.”

People arriving at work were met with plumes of smoke as crews from Marlborough and Calne tackled the fire.

“It was a bit dramatic,” said Toby Hassell, store manager of Landmark.

“I was walking across the road and it was just a sea of fire engines, ambulances and police officers and I saw the diesel running across the road.

“I got here a little bit after the fire had been put out and we weren’t able to open the store initially so the fire service could do a dangerous gases check because of the smoke that had been emitted from the bus.”

Firefighters left the scene by 10.50am and the road was reopened by 11.45am.

A spokesman for Stagecoach said: "One of our drivers was alerted by a fellow motorist to smoke coming from the rear of his vehicle as the bus pulled into a bus stop on High Street.

"Safety is our absolute priority. We will be carrying out an investigation into the cause of the incident.”

Diesel from the bus ran into the drains in the High Street which flow directly to the River Kennet with no cleaning process in between.

Riverside resident Val Compton photographed the diesel spill, which in one place ran past the nest of a coot.

Action for the River Kennet is concerned about the impact this will have on wildlife and is discussing with the Environment Agency whether volunteers can deploy oil-absorbent booms around drain outfalls to contain spills from the High Street in future.

Director of ARK Charlotte Hitchmough said: “This incident illustrates how vulnerable the river is to spills, pollution and run-off from the road.

“It is too early to tell whether the fuel spill will cause lasting harm, but it is a timely reminder that our road drains lead to the river, and whatever goes down them will end up in the Kennet.”

ARK is asking people to report pollution by calling the Environment Agency Incident Line on 0800 807060 and telling ARK where the problem hotspots are by emailing carolyn@riverkennet.org