Police were called to Alexia Square, near Crossharbour DLR station in Poplar, shortly after 6pm on Friday and found a man believed to have been in his late teens or early 20s with stab wounds.
Despite emergency services carrying out first aid the man was pronounced dead at the scene.
A second man, believed to be in his late teens, was rushed to hospital by London Ambulance Service.
A crime scene is in place and no arrests have been made, the Metropolitan Police said.
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