Photos and video posted on social media and by British news outlets showed the horses running along busy roads, dodging buses, taxis and other traffic.

Both were wearing saddles and bridles, with one apparently covered in blood on its chest and forelegs.

London's Metropolitan Police said it was "working with colleagues in the army to locate them".

A number of prestigious army regiments have stables in the British capital and horses are a regular sight around government buildings on Whitehall, Buckingham Palace, The Mall and in nearby Hyde Park.

The City of London Police, which polices the Square Mile financial district, said they were called at about 8:40 am (0740 GMT) about the loose horses.

"Our officers have contained two horses on the Highway near Limehouse," a statement read.

"We're waiting for an Army horse box to collect the horses and transport them to veterinary care."

The Daily Telegraph said up to five army horses had thrown their riders while they were being exercised and at least one soldier was injured.