Five military horses have thrown their riders and bolted through the streets of central London, causing rush hour chaos as they collided with vehicles and a double-decker bus.

The horses were part of the Household Cavalry and were part of a rehearsal with their military handlers when they became spooked.

Four people were injured – three soldiers and a cyclist – when the animals took off in fright after “building materials were dropped from height right next to them”.

“The ensuing shock caused all horses to bolt and unseated some riders,” Household Cavalry Mounted Regiment commanding officer Lieutenant Colonel Matt Woodward said.

Television images showed one saddled white horse covered in blood running through the street alongside another, black one.

The black horse slammed into a London taxi. One witness said car windows, boots and bonnets were smashed, including on a BMW.

All five equines were eventually recaptured. Two were found eight kilometres away in east London. All were receiving veterinary care.

One horse gallops towards a group of cyclists. Photo: Getty

The strange scenes unfolded near Buckingham Palace and the seat of the British government, with the runaway animals galloping past bewildered Londoners on their morning commutes on Wednesday (local time).

The horses belong to the Household Cavalry, which is the King’s official bodyguard and takes part in ceremonial duties. It is garrisoned at Hyde Park barracks, close to Buckingham Palace.

The BBC reports a group of six soldiers and seven horses were involved in a rehearsal for a major-general’s inspection. Every military unit taking part in the King’s birthday parade in June must pass a major-general’s inspection in advance.

One of the horses collides with a London taxi. Photo: Getty

“A number of military working horses became loose during a routine exercise this morning. All of the horses have now been recovered and returned to camp,” a British army spokesperson said.

“A number of personnel and horses have been injured and are receiving the appropriate medical attention.”

London’s Metropolitan Police had said authorities were working to locate “a number of horses that are currently loose in central London”, before confirming later that all had been accounted for.

Medical authorities said four people were taken to hospital after being injured.

-with AAP