A teenage boy was rushed to hospital with a head injury after a "disturbance" in South Harrow.
Metropolitan Police were called to Sherwood Road just before midnight on Saturday (July 7) and attended along with the London Ambulance Service to find a 17-year-old boy injured.
They also found two cars in the road that were damaged as well as two hammers, which police believe were used in the incident.
This was not confirmed by Metropolitan Police, however they did arrest a 26-year-old woman at the scene on suspicion of drink driving, violent disorder and grievous bodily harm.
She has since been released under investigation.
The boy was rushed to hospital but his injuries are not believed to be life-threatening or life-changing.
Police in Harrow are continuing to make enquiries in connection with the "disturbance".