All of the people arrested are believed to be in their 20s
Officers responded to reports of the robbery in Sedgefield Crescent at around 2.50pm on Wednesday, 24 March.
They searched the area and found four suspects, all aged in their 20s, in nearby Settle Road.
The men were detained on suspicion of robbery, possession of an offensive weapon and possession with intent to supply.
The incident took place near Draper’s Academy although no one from the school was reportedly involved.
For more on this story, and the latest on our other local and national news, listen to Time 107.5FM
Tags: Havering, Robbery, Harold Hill