Armed police at the scene in NortholtCredit:Ben Cawthra/LNP Police said items inside the property could be dangerous and officers have consequently not forced entry. Negotiators are present and a 200-metre cordon has been erected. A Metropolitan Police spokesman said: “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.” Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings. Armed police have surrounded a property in London after claims a man barricaded himself inside with “hazardous items”. Around 80 people have been evacuated from the area near Wood End Lane in Northolt, north west London, after officers descended on the street shortly before 1am. Steve Carroll, 42, told Get West London that armed police were using the nearby leisure centre car park due to an “emergency”.He said: “We got there around 8.20am for kids swimming lessons. When we arrived there was one car outside with lights on. By the time we parked in the leisure centre car park and walked round to the entrance there was 3 cars and 3 vans. Police cordon off Whitton Ave West #northolt and police all over Northolt Leisure centre. An “emergency” being announced on PA system.— Kaustav Bhattacharya (@jupiterorbit) October 22, 2016 She said: “When I eventually got there, five vans were parked at the leisure centre. We don’t know what is happening. I have never seen anything like this on such a mass scale in Northolt.”London Ambulance Service and London Fire Brigade staff are working with officers. “When we were coming out about 9.45am the car park was blocked off by police and there was police cars and vans everywhere. Armed police there too.”Dr Rekha Elaswarapu told the Evening Standard she was driving to the leisure centre at around 7.45am when she saw “police vans everwhere”. Just outside the 200 m police cordon in #Northolt . @metpoliceuk say it concerns ‘ one occupant and hazardous items ‘ … pic.twitter.com/rwgN00Oqkk— Ayshea Buksh (@AysheaBuksh) October 22, 2016 Police said items inside the property could be dangerousCredit:MAAA/ZDS They added that there was no suggestion the incident is terror related and said it was not linked to any other ongoing investigation or operation. “The priority of the Metropolitan Police Service is to bring this incident to a safe conclusion,” the spokesman added.