No one was injured during the incident (Credit: Google Maps)
Officers were called to Gale Street at around 7.50am and closed roads surrounding the area.
They detained the suspect, aged in his 20s, and discovered he was carrying an imitation firearm. He remains in police custody.
There were no reported injuries and officers are not looking for anyone else in connection with the incident.
Enquiries are ongoing and all roads have since been reopened.
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Tags: Dagenham, Barking and Dagenham, imitation firearm