Police are warning people to not go into Oxford Circus, a street very close by to the gay area of Soho, central London.
The Met are responding as if the incident is terrorist related.
They have told people on nearby Oxford Street to take cover inside buildings.
‘Oxford Circus Station is closed while we investigate a customer incident,’ Transport for London said, with Bond Street also closed.
No casualties have been reported at this stage.
PrEP advocate Greg Owen has reported he is in the middle of it, and is currently taking cover in French Connection.
‘Some seriously scary shit! Police everywhere!’ he’s tweeted.
‘Latest update from the police “we can’t give you specifics. But there’s been shots fired and explosives. So please stay in the shop and move to the back”.
— GrEG Owen (@Greg0wen) 24 November 2017
‘We’re now being moved away from the windows or downstairs. The shop is locked and police have whole area on lock down.’
This post will be updated with new information as it develops.
The Met Police have not found any evidence of shots fired or casualties.
In a statement, they said: ‘To date police have not located any trace of any suspects, evidence of shots fired or causalities.
‘Officers continue to work with colleagues from British Transport Police in the area of Oxford Circus.
‘Updates will be provided as soon as we have them.
‘If you are in building stay in a building, if you are on the street in Oxford Street leave the area.
‘Officers are continuing to search the area.’
Police have confirmed Oxford Circus Station and Bond Street Station have now re-opened.
Owen has said he and the rest of the people trapped in the lock down are now allowed to leave the shop.