An 18-year-old man attended a north London police station on Monday, 8 November and was arrested on suspicion of murder.
A 21-year-old man was also arrested on suspicion of murder at an address in Tower Hamlets on Tuesday, 9 November.
A 28-year-old man was arrested on suspicion of murder on Tuesday, 9 November.
All three remain in police custody.
An investigation was launched after police were called to Navigation Road, Tower Hamlets at 8.43am on Saturday, 6 November by the London Ambulance Service to reports of an unresponsive man.
Officers attended with paramedics and found Mohammed suffering stab injuries; he was pronounced dead at the scene.
He has been identified as Mohammed Aqil Mahdi, 22, who lived in Camden.
His next of kin have been informed and are being supported by specialist officers.
A post mortem examination will take place in due course.
The investigation is being led by homicide detectives from the Specialist Crime Command.
Detective Chief Inspector Laurence Smith,said: “The inquiry is progressing, but we are still looking for anyone with information. We need the public’s support to make London a safer place for everyone and you can assist by picking up the phone and telling us what you know. If you don’t want to give your name, call Crimestoppers anonymously, but please tell us what you know.”
Any witnesses or anyone with any information is asked to contact police on 101 via Twitter @MetCC. Please quote CAD 2171/06NOV
To give information anonymously contact Crimestoppers on 0800 555 111 or online at crimestoppers-uk.org.