People expressed horror after a hammer attack in a residential street in which a 17-year-old man was taken to hospital with head injuries.

The attack took place in Sherwood Road, South Harrow, at around 11.35pm on Saturday. 

One witness who saw the violence from their window said they had just turned out the lights when they heard a noise that sounded like “heavy machinery" crashing outside.

The witness, who did not want to be named, claimed two cars came speeding around the corner from Northolt Road and collided.

The witness said: “They were skidding down the road crunched up side by side and stopped when they crashed into a parked van further down.”

Residents heard men shouting and glass smashing before about “20 to 30 men in their mid-20s” came running down holding weapons that they said looked like “batons or baseball bats”.

As neighbours called the police, more men appeared “screaming and jumping on cars” and smashing the windows before dragging people out of on car.

The witness said: “I could see a man being hit violently and repeatedly over the head. I could hear he was crying and I could see him looking desperate.

“I noticed other neighbours screaming from their windows: ‘Stop’ and ‘I’m calling the police’.

"It felt like someone was going to die.”

The witness said the incident was over within minutes, but one woman returned to retrieve a bag and three men shouted after her, “we can see you, slut” before she ran away and the men dispersed.

By the time police arrived the area was clear.

The witness continued: “More neighbours came out and we were all stunned. An ambulance was called because a man was found injured in someone's front garden. The police told us that we needed to get inside because the place was now a crime scene.

“I felt shaken and like I wanted to get out of South Harrow.”

Shortly after news of the violence was published in a Harrow online community group, there were calls for a petition and “political involvement” and “urgent action, including immediately reversing police cuts”.

Police confirmed reports of a “disturbance” in Sherwood Road on Saturday, adding a 17-year-old man had been taken to a west London hospital with head injuries that are not believed to be life-threatening.

They also confirmed two vehicles had been damaged, two hammers had “been used” and seized and that that a 26-year-old woman had been arrested at the scene on suspicion of drink-driving, violent disorder and grievous bodily harm. She has since been released.

Community activist and campaigner Kuha Kumaran said: “I have been campaigning against violent crime in Harrow for many years. I raised a petition about crime in the area last year, the same issues are cropping up again.

“Central government have promised to give extra funding for local policing. They have a moral obligation to pull themselves together; the people in South Harrow have been crying out for direction which hasn’t been done.”