Two more arrests have been made in connection with the murder of a 17-year-old boy in North West London on 8 November.
Officers arrested a 21-year-old man and a 19-year-old man on suspicion of murder and attempted murder on 12 November. The pair have been taken to East London police stations, where they remain in custody.
Police and ambulance services were called to Belvedere Way, Kenton, at 12.36 am on 8 November following reports of a stabbing. They found 17-year-old Che Labastide-Wellington, who had been stabbed in the heart.
Police said he had got into a fight with a group of youths who had tried to gain entry to a party. He was taken by air ambulance to Northwick Park Hospital, where he was pronounced dead about an hour later.
Just a day later, in an unrelated incident, 18-year-old Alfie Stone became the 13th teenager to be stabbed to death in London this year.
Two boys, aged 15 and 16, were arrested on suspicion of murder and taken to a North London police station, where they have been bailed until mid-December. A 14-year-old was arrested on suspicion of possession of an offensive weapon, and was bailed until January 2016.
Another teenage boy, aged 16, was also stabbed during the incident and is currently being treated in a North London hospital, where his condition is described as stable.