WASHINGTON (AP) — Authorities in Washington evacuated the Canadian embassy and shut down nearby streets to investigate a letter that contained a suspicious substance.

Embassy spokesman Chris Plunkett says a suspicious letter was found by mailroom staff Friday morning.

Metropolitan Police Department spokesman Araz Alali says police were called at about 9 a.m. and gave the all-clear at approximately 10: 45. Alali says no harmful materials were found, but the Secret Service is investigating.

Streets were shut down in the area on Friday morning but all have since reopened.

It was not immediately clear what substance the letter contained.

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