Four of the five boys have now been bailed to return to an East London police station in late January 2015 pending further enquiries.
The fifth, arrested this morning, remains in custody.
Metropolitan police said a fifth boy, aged 13, had been arrested on suspicion of murder just before midday on Monday.
"He has been taken to an East London police station where he remains in custody," a statement said.
Original story below.
Four boys aged 13 and 14 have been arrested on suspicion of murder after a 52-year-old man was stabbed to death in north London on Sunday.
Police said they believed they knew the identity of the victim, who was with a woman, but were waiting for formal identification.
Four boys have been arrested on suspicion of murder and remain in custody at a north London police station.
Detective chief inspector Neale Baldock of the Homicide and Major Crime Command said:
Our initial enquiries have established that there was a supervised party taking place at another address within the block and the group of males were trying to gain access to this.
The victim and this group were not known to each other – what started as a minor verbal altercation has escalated into a shocking act of violence.