Counter-terrorism detectives are investigating after two suspected bombs were found in an empty flat.
Officers were called to a property being refurbished in Craven Park, Harlesden, in north-west London, at 9.30am on Wednesday.
The block of flats was evacuated and roads were closed after specialist officers assessed them as being suspected improvised explosive devices, Scotland Yard said.
Both items were taken for forensic examination.
Further searches took place before the area was deemed safe and the cordon was lifted at around 6pm, the Metropolitan Police said.
Chief Superintendent Simon Rose said: “The next stage is to investigate how and why the two devices came to be in this flat and detectives from the Counter Terrorism Command will be leading this.
“The public’s safety is our top priority, and I would like to pay tribute to the specialist officers who attended and were able to safely recover the devices.
“I also want to reassure the local community that we have carried out precautionary searches in the surrounding area to make sure there was nothing else of a similar nature nearby.”
He appealed for anyone with information to come forward.
There have been no arrests.