Police have shot dead a man who was threatening a woman with a knife.
Residents in a leafy street in north London said they woke up at around 1am to hear a volley of gunshots "like fireworks" and saw the area swamped with police cars and armed officers.
Scotland Yard said the man, 40, died on his way to hospital - around 20 minutes later.
It is the first fatal shooting by a Metropolitan Police marksman since the death of Mark Duggan in 2011.
Photos taken by neighbours show a middle-aged woman in a pink blanket being comforted by a female police officer as she was led away from the house in Shepperton Road in Islington. She was not harmed but was treated for shock.
Police had sent a negotiator to the scene at 11.19pm last night following reports that the man had broken into a house. The man and woman involved are believed to have known each other.
Today investigators from watchdog the Independent Police Complaints Commission were at the scene of the shooting.
Lyssa Barber, a neighbour who works in recruitment for a bank in the City, said: "I was woken up to shouts and immediately afterwards to what sounded like four or five bangs. They were gunshots.
"I think I heard five gunshots, but a gunshot in real life doesn't sound like it does on TV. It sounded like loud bangs on a door. Bang, bang, bang. Then I realised, if it's somebody banging on the door, why can I hear it?
"We saw the ambulance and police. There were eight police vehicles I could see from my window, and I saw five armed officers.
"The ambulance arrived as I was looking out of my window. Police came out of the house. We could see someone being led away. I'm fairly sure they were wearing pink and had to be supported by officers."
She said she was shocked such a scene could unfold on her doorstep.
She said: "I think a couple lived in the house. I think they were middle-aged, maybe in their 50s.
"It's happening right outside my house and it's the sort of thing you read about in the papers."
Neighbours said police cordoned off the street last night and were stopping some residents from returning to their homes. Shortly afterwards they heard gunshots.
A 36-year-old man, who works in advertising but did not want to be named, said: "I arrived home and saw police, who escorted me to my house. Some other residents weren't allowed back into their homes.
"I saw armed officers, those special police who had arms on. I saw around three or four of them.
"Later when I was inside my house I heard shots.
"I looked outside my window ... she was in her 40s and 50s wearing pyjamas with a pink blanket wrapped around her."
Daniel Keane, 28, an office worker who lives in the street, said: "I thought I heard fireworks, that's what it sounded like to me.
"It was around 1am.
"The shots didn't last long at all, but it wasn't a standard type of firework sound. It sounded different.
"I also heard some shouts, but they weren't audible."
The street remains cordoned off with more than a dozen police officers are still at the scene and a nursery in the street is closed.
The Metropolitan Police said in a statement: "As in any shooting, officers from the Met's Directorate of Professional Standards (DPS) have been informed and this incident has been referred to the Independent Police Complaints Commission (IPCC)."
A female neighbour, who asked not to be named, said: "I heard lots of shots - three or four. Like a bonfire. I've never heard anything like it before. It was really scary.
"There were a lot of police with guns. It was very scary. The people who lived there moved in around a year ago - I thought the man was her son."