As fears of anthrax letters continued to spread around the globe, the Prime Minister's Official Residence, the Defense Agency and some media organizations on Wednesday received envelopes containing white powder that turned out to be starch.

According to police officials, analyses showed there was no danger. In most cases, the name of the sender was identical, and investigators are probing the incidents as hoaxes.

The mail addressed to Prime Minister Junichiro Koizumi arrived at his official residence in the Nagata-cho district of Tokyo's Chiyoda Ward at around 10:45 a.m. A staffer opened it and found a typed letter and a plastic bag with the powdery substance, police said.

The post was sent from Osaka, and the letter denounced the U.S. military action in Afghanistan, according to the police.

At the Defense Agency, white powder was enclosed in an envelope addressed to Director General Gen Nakatani.

Chief Cabinet Secretary Yasuo Fukuda expressed concern at a regular news conference that the pranks could cause social unease.

A series of anthrax cases initiated through the mail have been reported in the United States, fueling fears over so-called biological terrorism. The State Department have told U.S. diplomatic establishments overseas to stock antibiotics to deal with possible anthrax infection.

In another case from Sept. 24, a counterfeit check covered with powder was sent from the U.S. to a biotechnology device sales company in Kobe, prompting an investigation by Hyogo Prefectural Police.

No one who handled the envelope has shown any symptoms, and police believe the incident to be another prank.

U.S. consulate scare

OSAKA -- An envelope containing a white powder arrived at the U.S. Consulate General for the Osaka-Kobe area Wednesday morning, the Osaka police said.

The consulate general, in Osaka's Kita Ward, notified the police shortly after 11 a.m. that a small amount of powder had spilled out of the envelope when a mail-handling employee examined it. The employee did not open the mail, according to the police. The police said they dispatched members of a special unit to the consulate general to investigate, and they plan to ask experts to examine the powder.

According to investigations, the envelope had apparently been mailed from Osaka and was addressed to U.S. Consul General Robert Ludan. It was thought to be a hoax

The sender typed the address and the consul general's name in Japanese and wrote "Confidential" on the envelope in Japanese.

The employee who handled the envelope and several other people at the consulate who may have touched it have been placed in an isolation area, police said.

Police officers wearing protective suits entered the consulate general around noon.

Investigators said the incident could be another prank.