A serious disease outbreak in Thailand's northern province of Nan put weapon specialists and U.S. disease investigators on full alert on Monday.

Almost 150 people in the province have been stricken by botulism, a rare yet lethal bacterial disease that could potentially be used as a biological weapon.

Health authorities have sought international assistance treating the patients.

U.S. military biological weapons experts and the World Health Organization disease specialists have been flown into Nan, said Thai Disease Control Department chief Thawat Suntharacharn.

Since March 4, 143 villagers in Nan's Ban Luang district have been diagnosed as suffering from botulism, a disease caused by toxins produced by several members of a group of bacteria known as Clostridium botulinum.

All of the patients reportedly have eaten dishes containing preserved bamboo shoots from the same batch at a merit-making feast in their village last week. Shortly after eating the shoots they began to suffer similar symptoms, including vomiting, diarrhea, difficult swallowing, dry mouth and muscle weakness, Nan chief health officer Dr. Pisit Sriprasert said on Sunday.

Of the 147 patients, 33 are currently breathing with the aid of respirators, he said.

"This bacterium is among three strains that can be used as a biological warfare agent -- the others are anthrax and smallpox," said Thawat.

Fears of a biological attack arose because of the number of people falling ill at one time, he added.

Source: Xinhua