Detectives investigating a stabbing in Harrow that left a teenager critically injured have made four arrests.
The four (all aged late teens/early 20s) were arrested on Monday, 21 November on suspicion of attempted murder.
They were taken to a north London police station before being released on bail until early December pending further enquiries.
The victim remains at central London hospital in a critical condition.
Detectives continue to appeal for witnesses and information.
On Friday, 18 November police were called at approximately 17:10hrs to reports of a man stabbed near to South Harrow Underground Station, outside Kebabish takeaway on Northolt Road, Harrow.
Officers and London Ambulance Service attended and found a 19-year-old man (victim 1) suffering a stab wound.
Due to the severity of the victim's injuries, detectives from the Homicide and Major Crime Command are investigating.
At this early stage, it is thought that the victim was attacked by a group of males, all of whom are described as black and believed to be aged in their teens or 20s.
The victim had been riding his bicycle shortly before the stabbing. This bicycle was recovered near to the scene.
A 17-year-old male [victim 2] also sustained a minor laceration to his abdomen during the incident. He was taken to hospital for treatment and later discharged.
Any witnesses or anyone with information that may assist the inquiry is asked to call the incident room on 020 8358 0400.
To give information anonymously contact Crimestoppers on 0800 555 111 or visit crimestoppers-uk.org.