Several people remain unaccounted for after an explosion and fire at a block of flats. At least two people were injured when the blast ripped through the building in Oxford, causing it to collapse. It is not known what caused the incident in the west of the city on Tuesday afternoon. Oxfordshire County Council said around 40 firefighters joined the rescue operation, with the help of urban search and rescue teams from Buckinghamshire and Milton Keynes. A spokesman said: 'The emergency services were contacted at 4.45pm following reports of an explosion, a fire and the collapse of a property. 'Two people have been treated for minor injuries and one was taken to the John Radcliffe Hospital in Oxford. 'A small number of people are unaccounted for in this ongoing investigation.' A number of surrounding buildings were evacuated and members of the public were advised to avoid the area. South Central Ambulance Service said a male was treated at the scene for smoke inhalation and a female has been taken to hospital for treatment for minor injuries. Emergency services were called to the Osney Lane and Gibbs Crescent area at 4.45pm on Tuesday, Thames Valley Police said. Thames Valley Police Chief Inspector Marc Tarbit, deputy local police area commander for Oxford, said: 'Our officers are currently on the scene working closely with our colleagues from the other emergency services. 'We are continuing to ask members of the public to please avoid the area to allow the emergency services to work at the scene. 'I also appreciate incidents of this nature cause disruption to the community so I would like to thank people locally for their patience and understanding while we are working to respond to the incident.'