More than 100 firefighters took five hours to bring the blaze, in Covent Garden, under control.

The fire broke out in an office block in a converted warehouse on Earlham Street on Thursday evening.

Nobody was seriously hurt, although two people were rescued by ladder from the five-storey building and taken to hospital suffering minor smoke inhalation.

BBC correspondent Carole Jones, who was at the scene, said the performance of musical Blood Brothers at the nearby Phoenix Theatre had to be abandoned after the audience began coughing because of the smoke.

Fire engines hampered

Police also cleared the nearby Cambridge Theatre of hundreds of people who had been hoping to watch a performance of the musical Grease.

Ms Jones said the fire took hold very quickly, because the building was old and the recent warm weather meant the timbers had dried out and become extremely flammable.

Fire engines rushing to the scene initially found it difficult to gain access, she said, because of the narrowness of the streets in the area.

Police said there were no immediate indications that the fire was suspicious.