A suspicious package containing white powder found near CNN's office at the United Nations turned out to be harmless, but 20 journalists and U.N. staff members were decontaminated as a precaution, New York police said.

Det. Kevin Czartoryski said late Friday that tests on the substance had been completed "and it was non-toxic."

After preliminary testing, U.N. associate spokesman Farhan Haq said "It appears to be flour."

The discovery of the package near CNN's office on the fourth floor of U.N. headquarters overlooking the East River brought New York police hazardous material experts in yellow and white space suits to the 39-story building.

U.N. headquarters was not evacuated, but U.N. security officers closed off part of the fourth floor as well as a corridor off the main lobby on the ground floor near a security office where the package was taken.

Czartoryski said 20 people who came into contact with the substance were decontaminated.

They had to wash their hands, face, hair and other exposed areas, seal their clothes in a bag, and wear a special white decontaminated suits to go home.

Haq said it was not clear whether the package was in CNN's mailbox, in a mailbag on the floor nearby, or elsewhere in the corridor. It was addressed to a news organization, which was not identified.

U.N. security officers immediately informed the New York City Police Department and the Department of Environmental Protection who dispatched teams to examine and test the package along with U.N. experts, Haq said.

The Associated Press office at the U.N., which is near CNN, was initially closed off. U.N. security officers later allowed AP reporters to leave, but when they returned they were again ordered to remain in the office.