Builders have found an unexploded World War II bomb in Wembley.
Officers were called to a building site in Empire Way at around 3pm, after workers discovered what appeared to be an antique device.
The bomb is believed to weigh around 50kg.
Residents and traders have been evacuated from nearby buildings, and a 400m cordon has been erected in the area, the Metropolitan Police said in a statement.
Brent Civic centre is among the buildings closed over the incident, the Brent and Kilburn Times reported.
Roads in the surrounding area near Empire Way have been closed while police help to assist those who have been evacuated from properties.
Experts will now work to remove the bomb from the site, a police spokesman told The Independent.
The discovery comes after a separate World War II bomb was found in Bermondsey, South London.
The Metropolitan Police force said the device was a 'SA' 250kg WWII German air-dropped bomb.Reuse content