A policeman has been taken to hospital after being shot during an armed raid in east London.
The officer, who is stable in hospital with his family by his bedside, was shot in the shoulder in broad daylight in the middle of the street in Hackney.
Locals said the officer, named locally as Nick, was chasing suspects fleeing the raid when one of them turned around and shot him at 12.45pm.
Residents said Clarissa Road in Haggerston was lined with undercover police in cars when "at least two shots" rang out.
Business owner David Salvester, 28, said it was obvious they were on an undercover operation when one plain-clothes officer shouted: "Nick's been shot."
Mr Salvester said: "We were in the house and we heard a bunch of yelling.
"We went outside and there was a bunch of officers in green with their dogs.
"They had helmets and machine guns, I think.
"That's the point we heard the gun fire.
"They were all scrambling about.
"It was two shots, I think.
"The whole road was filled with undercover police.
"They all burst out of their cars (when the shots went off).
"Then there was a woman shouting: 'Nick's been shot, Nick's been shot'.
"She started getting all her first aid stuff out of the car.
"She was calling out a lot.
"There was obviously some kind of raid."
He said local people began shouting at police to tell them which way the suspect went.
He said: "We grew up in LA so we are more used to gunshots over there, not here."
Kaner Korbay, who owns nearby dry cleaners Bree-Zee, said: "There was a raid on a house in Scriven Street, they tried to get away and the police were chasing them.
"One of them shot the policeman.
"Right in the middle of the street, the centre of Haggerston Road.
"I heard the noise of the gun, two rounds I think.
"Within 30 seconds the police were everywhere, blocking the road.
"I saw the police officer getting treated with his shirt off.
"I think he was shot on his shoulder, they were covering his shoulder with bandages.
"Within five minutes he was taken to hospital by air ambulance, it landed in Haggerston Park.
"I saw one of the guys in handcuffs next to the wall."
He added: "There were undercover officers and police officers with guns running around everywhere.
"They were armed with machine guns."
A man, 31, was arrested at the scene and a non-police firearm was recovered, the Met said.
The injured officer was taken to an east London hospital by air ambulance where he remains.
The Metropolitan Police said officers from its Specialist Firearms Command (SCO19) and Trident Area Crime Command had been taking part in an "authorised firearms operation" when the shooting happened.
Commander Duncan Ball said he was unable to state for operational reasons whether any shots were fired by police during the incident.
But he praised the "tireless" actions of police which he said demonstrated officers' selfless dedication to duty.
He said: "This incident reveals the very real risks our police officers face on a day to day basis while protecting the safety of Londoners."
Police are investigating the circumstances behind the shooting.
Steve White, chairman of the Police Federation of England and Wales, said: "So soon after the tragic death of an officer on Merseyside, this incident once again reminds us of the dangers faced by officers policing in 2015."