Police in New York City have responded to a sixth report this week of powder in an envelope at a foreign mission to the United Nations.

Sgt. Reginald Watkins said officers responded about 1 a.m. Wednesday at the Russian Mission on the Upper East Side of Manhattan. Initial tests indicated it was harmless.

The missions to the United Kingdom and Germany received similar envelopes on Tuesday. On Monday, three arrived at the missions of France, Austria and Uzbekistan.

NYPD spokesman Paul Browne said three of the envelopes contained flour. Additional tests were being done on the others.

Some of the letters bore a one-line message: “Al-Qaeda FBI in America.”