Emergency services scrambled to the scene in London Road at around 6.30pm.
Witnesses said two men were treated by medics, one of which was wounded in the arm, the Barking and Dagenham Post reports.
Other witnesses said officers and paramedics were seen entering a restaurant on London Road.
Pictures from the scene show a police van blocking traffic from entering one end of the high street.
A Metropolitan Police spokeswoman said the condition of the victim is not yet known.
This is a breaking story, more to follow…
Source : EXPRESS