A woman was stabbed to death and a young man was left fighting for his life in a “machine gun attack” as London was hit by a night of shocking violence.

Three other men were stabbed in separate incidents that occurred in the capital within hours of each other, prompting concerns that violence was “rampant” in parts of the capital.

Police asked for anyone who witnessed the violence to come forward and share any evidence they may have.

Three of the incidents, including the fatal stabbing and the shooting, happened in Brent, prompting police to reassure residents that it is a "safe and vibrant borough".

The young man who was shot is believed to have been the victim of a machine gun attack after witnesses described hearing “semi-automatic” gunfire.

The victim, aged in his twenties, was found with gunshot wounds on the Stonebridge estate in Harlesden shortly after 8.30pm on Thursday.

He was treated at the scene and rushed to hospital where he is critical. The road remained sealed off today and a silver car that appeared to be peppered with bullet holes was covered with a tent.

A witness said: “I was walking up Shakespeare Road when I heard about 15 shots. They were in quick succession. The victim was slumped in the front seat and his brother ran outside too.” He said a car sped off up the road past him.

One woman said the victim was shot with a “machine gun” as he arrived at his home. She said: “Apparently a car pulled up alongside him while he was sitting in his car. He’s a good lad, I don’t understand why this has happened.”

Geoff Lamp, 35, a father of one, said: “It sounded like a semi-automatic.”

Another resident, George Nayinda, 50, said: “I came downstairs to check on my kids and make sure no bullets had come through the windows. It’s not safe to bring kids up here. Guns are rampant.”

At around 10.30pm, a man was stabbed in Rainborough Close – just over a mile away from the shooting.

The victim, believed to be in his twenties, was in a life-threatening condition and the attack prompted police to issue a Section 60 order to give the extra powers to carry out stop and searches on the Stonebridge estate amid fears of tit-for-tat gang attacks.

Hours later, at around 2.30am, a woman was attacked in a flat in Neasden Lane, also in Brent.

Police and ambulance crews were called at 2.32am and treated her at the scene but she died shortly afterwards. A 43-year-old man, who is known to the victim, was arrested on suspicion of murder.

Brent Superintendent Tim Alexander said: "Overnight we found ourselves in the unusual position of having to deal with three violent incidents in our borough of Brent.

"I understand the community’s concerns regarding last night’s events, but I would like to reassure the people who live and work in Brent that we remain a safe and vibrant

"The community can expect to see extra officers on the streets of Brent over the coming days and I would urge anyone who has any concerns to feel free to approach them."

Also during the night a 23-year-old man was found with stab injuries in Creek Road, Deptford while a man aged 28 was knifed on the Old Kent Road in the early hours. Police were unable to say what condition they were in this morning.

Meanwhile detectives investigating the murder of a man, 42, in Chelsea on Wednesday night said one line of inquiry is he had been attacked in a robbery. The victim, said to be a father of three, was found in Cathcart Road but is thought to have been attacked nearby.

Anyone with information should call police on 101 or ring Crimestoppers on 0800 555 111.