An envelope containing a letter and an unidentified yellow powder has been found at the U.S. Embassy in the Malaysian capital of Kuala Lumpur, prompting immediate precautions but no closing of the embassy. It was the second such incident at a U.S. embassy in Asia in a week.

Embassy spokesman Frank Whitaker says Malaysia's Hazardous Materials Unit was called in as soon as an embassy employee opened the envelope Monday morning and discovered the powder. He said the embassy staff was waiting to hear whether the substance was dangerous.

"They came in and inspected the area, they have taken the substance for further testin," says Mr. Whitaker. "We frankly at this point don't know the results of that testing."

There was a similar incident last week at the U.S. Embassy in the Sri Lankan capital, Colombo. The embassy was closed for four days, but tests on the powder there showed it to be harmless.

Mr. Whitaker refused to speculate on whether the two incidents were connected, or what the motivation for sending the letters might have been. "At this point I'm not going to make any comments about that linkage," he says. "We simply don't know that much at this stage."

The fear is that the powder might contain anthrax or other toxins. Five people were killed in the United States in late 2001 when powder containing anthrax spores was mailed to several media organizations and the offices of two U.S. senators.

Mr. Whitaker says the embassy in Kuala Lumpur was not closed, but staff members who came into contact with Monday's letter were given initial treatment.

The same embassy received an envelope containing a suspicious powder in 2001. Mr. Whitaker said in that case, the powder turned out to be harmless.