An armed stand off is ongoing in Wood Lane, Northolt, as a man has barricaded himself into a property with 'dangerous items', police have said.
Eighty people in the surrounding area have been evacuated and firearms officers and police negotiators are at the scene.
Officers have not attempted to enter the property out of "concerns for the safety of the man and responding officers," according to a Metropolitan Police statement.
A police spokesman said: “Police cordons are in place, at a 200-metre radius, to facilitate the ongoing policing operation.
“At this stage police believe there is one man inside the address.
“Whilst it is not known what the man has inside the property, police are treating seriously reports that the items could be dangerous and that attempts have been made by the man to prevent access to the address.
“Police are working with the London Ambulance Service; London Fire Brigade and the Local Authority.”
More follows....