Armed police are in a stand-off with a man who has reportedly barricaded himself inside a property and could have “hazardous items”.standAbout 80 people have been evacuated from their homes following the alert in Wood End Lane, Northolt, north-west London. Police negotiators are also at the scene and a 400-metre wide cordon has been put up around the property.

Officers said they are treating seriously reports that the items could be dangerous and that the man has tried to prevent access to the address. Police were called to the site just before 1am this morning after fears were raised for the man inside and possibly hazardous items there.

Officers have not attempted to get into the property amid concerns for their safety as well as his. Local residents have been temporarily re-housed, also for safety reasons.

Detectives said there was no suggestion that the incident was terror-related and was not part of an ongoing police operation. The Met said in a statement: “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.”