Shoppers have been evacuated from Oxford Street outlets due to a gas leak in the area.
Police say they were called to reports of a gas leak at about 1.05pm this afternoon.
The London Fire Brigade also attended as about 400 people from nearby buildings were evacuated from the scene as a precaution.
A large emergency service presence was seen in the popular shopping district, with several roads in the central London area shut down by police.
Metropolitan Police say there are no reports of injuries.
Police shut down Poland Street, Berwick Street, Oxford Street, Noel Street, Wardour Street and Great Marlborough Street.
The force tweeted: "Please can we make you aware of a gas leak that has been identified at Poland St W1F. LFB and Police are in attendance.
"Nearby Buildings are currently being evacuated, road closures and cordons have been put in place as a safety precaution."
One video from the scene shows more than a dozen firefighters on Poland Street.
The LFB said two fire engines from Kensington and Brixton attended.
A cordon remains in place this afternoon.
A Met Police spokesperson told MyLondon: "Police are assisting following a gas leak. Officers were called at 13:05hrs on Monday, 4 April in the Poland Street area, in Westminster to a report of a gas leak.
"Officers, London Ambulance Service and London Fire Brigade have attended the scene. We are not aware of reports of any injuries.
"Local road closures are in place and some buildings have been evacuated while emergency services deal."
A London Fire Brigade spokesperson told the Mirror Online: "Firefighters were called to reports of a gas leak at the junction of Poland Street and Noel Street in Soho this afternoon.
"A gas main at ground floor level had ruptured. Crews worked with gas engineers and the supply was isolated.
"Around 400 residents and staff were evacuated from buildings in the surrounding area as a precaution.
"The Brigade was called at 1304 and the incident was over for firefighters by 1450, but crews remain on scene standing by while gas levels reduce.
"Two fire engines from Brixton and Kensington fire stations were in attendance."
