Kelyan Bokassa was found injured onboard a 472 bus in Woolwich Church Street just before 2.30pm on January 7.
Officers and London Ambulance Service crews attended, however, the 14-year-old was pronounced dead shortly after.
A 15-year-old boy and a 16-year-old boy were arrested on suspicion of murder today (January 15).
They both remain in custody.
A 44-year-old woman was arrested on suspicion of assisting an offender, she also remains in custody.
Detective Chief Inspector Sarah Lee who is leading on the investigation said: “While these arrests mark a significant step forward in this investigation, we continue to appeal for anyone with information about Keylan’s murder to come forward and speak to us.
“I would like to thank officers for working around the clock in order to locate our suspects and praise the Woolwich community for their on-going support and patience whilst we have carried out our investigation.
“I know that this incident deeply affected you all, and I hope that these two arrests reassure you that we are doing everything to tackle violent offenders across London.”
The investigation remains on-going.
Anyone with information that could assist the investigation is asked to call 101, quoting the reference 3795/07Jan.
You can also contact the independent charity Crimestoppers anonymously on 0800 555 111.
