A 19-year-old had a thumb sliced off his hand during a violent fight in Keller Crescent, Manor Park, last night.
He and a second young man were taken to hospital.
Police were called to a fight at 10.30pm where they found the injured men.
The Crescent along with Gladding Road was shut down for a time.
A Scotland Yard spokesman said two men have been arrested and are being questioned.
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