POLICE have refused to disclose why armed officers raided a house in Thornton Heath on Tuesday evening.
The property in Headcorn Road was surrounded by armed police at around 6pm.
They forced entry into the house which was evacuated, along with several adjacent homes.
It is understood no arrests were made. People were allowed to return to their homes less than an hour later.
This morning (Wednesday) Scotland Yard said no details of what happened would be released.
A spokeswoman told the Advertiser: "We were in the Croydon area for a pre-planned operation which we're not prepared to discuss further for operational reasons."
The police helicopter and a dog unit were also sent to the scene.
