A 13-year-old girl was arrested after cops discovered a converted assault rifle beneath a wardrobe during an armed raid.

Cops armed with sub-machine guns sealed off the Monks Hill Estate, in Selsdon, on Tuesday searching for the automatic weapon which was hidden in one estate’s many flats.

Intelligence received by the Operation Aries gang unit sparked a huge operation in Tedder Road to recover the weapon, which is thought to have been reactivated from a decommissioned rifle, before it could be used against anyone in the borough.

Around 15 CO19 armed officers carrying hydraulic battering rams and combat shields raced to the flat to recover the weapon.

Roads were cordoned off and people told to stay in their houses as the heavily armed officers made their way to the building.

Cops then used a hydraulic door ram to force the door open and stormed into the flat shouting: “Armed police, get on the ground.”

After armed police secured the flat Sergeant Darin Birmingham and his team searched the rooms, uncovering the weapon wrapped in clothes under a wardrobe.

A police spokesman said: "A girl - aged 13-years - was arrested for possession of a firearm and taken to a south London police station. She has been bailed to return. Further arrests are anticipated."

Sergeant Darin Birmingham said: “We received information that the young man living here, who is a known gang member, had access to firearms.

“We pieced together the information we had and decided to act immediately in case the firearm was used.

“The people of Croydon need to know that if we get this information we will act as swiftly as we can to take these guns off the streets.

“If you mess around with weapons we will be at your front door and you will come face to face with an armed response unit, we will not tolerate the use of weapons in this borough.”

Sgt Birmingham and his four man team coordinated the raid which, once given clearance, was rolled out within a matter of hours.

PC Ben Summerhayes said: “The recovery of this weapon shows that Croydon Police will take all calls regarding firearm offences very seriously.

"If someone you know has a firearm contact Croydon police and we will deal with it."

• What do you think? Let us know by email here, phone the newsdesk on 020 8330 9555 or leave a comment below.