A dozen employees of the Manila Post Office are currently placed under quarantine after possibly being exposed to a letter addressed to the United States Embassy in Manila suspected of containing anthrax.

The twelve employees, who all work at the lock-box section of the post office, are presumed to have handled a letter addressed to the US Embassy in Manila which was suspected of containing anthrax.

The US Embassy is assigned PO Box 151 inside the lock-box section, which is now temporarily closed.

The letter suspected to contain anthrax was first noticed when the US Embassy's messenger picked up mail from the said PO Box.

The embassy was alarmed when they noticed the letter, which came from Houston, Texas.

The letter was immediately brought by the embassy's FBI agents and the Bureau of Fire Protection (BFP) Hazardous Materials section to the Research Institute for Tropical Medicine (RITM) in Alabang for testing.

The BFP HazMat team also went to the lock-box area to decontaminate the room and to examine the employees.

Despite not yet proving the mail actually contained anthrax, authorities said the precautionary measures were taken to ensure the safety of everyone involved.

The US Embassy said they were being careful because around 80 US foreign outposts around the world have been sent mail allegedly containing anthrax since September 2008.

They also said there is no cause for alarm yet since there is no concrete proof yet that the mail contained anthrax.

Meanwhile, other employees of the post office are also worried about possibly being exposed to anthrax, since mail pass through many people in the post office before going into the lock boxes.

Anthrax is considered as a biological weapon that can be used as a weapon of mass destruction, and is commonly in the form of fine, odorless, white powder.

In 2001, the United States had an anthrax scare, where several people got infected after being exposed to mail bearing the virus.-- With a report from Maan Macapagal, ABS-CBN News