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.

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.

The terrifying letter campaign is eerily similar to the 2001 anthrax attacks.

But unlike the envelopes of eight years ago, the contents of which killed five people and infected 17 others, police said the most recent mailings did not contain the deadly anthrax spores. They are believed to be part of an elaborate hoax. The white material has been deemed harmless.

“Anybody that thinks that it’s a joke is making a very bad mistake. If we apprehend you you’re going to face criminal charges,” Mayor Michael Bloomberg said.

HAZMAT teams have taken no chances, decontaminating 33 people who worked at the French, Uzbekistan and Austrian buildings. The secretary at the German Consulate was also decontaminated.

“We caution all of the missions here at the United Nations to be careful with their mail and if they see any suspicious envelopes not to open them. If they do open them to segregate them and call police immediately,” NYPD Commissioner Ray Kelly said.

(Source: CBS2 HD)