Nearly 2,000 fire ants have been discovered in Kyoto in a shipping container that arrived from China, local authorities said Saturday.

The ants, including two queens, were found Thursday along with eggs and pupae in a warehouse in the city of Muko, confirming the presence of the venomous species in the prefecture for the first time.

The ants were exterminated, but the Kyoto Prefectural Government and the Environment Ministry plan to search the area for more just in case.

The container was filled with blankets shipped from a factory on Hainan Island on Sept. 20. It arrived at the port of Osaka via Hong Kong before being brought to the warehouse in Kyoto.

Fire ants are native to South America but have been found in Tokyo and 11 other prefectures since turning up for the first time in May, in Amagasaki, Hyogo Prefecture, according to the ministry.

The small, aggressive ants are known for their heavily populated nests and a painful sting that can cause anaphylaxis in some cases.

Though fire ants are a common nuisance in North America and China, the media and the government have been playing up fire ants as a deadly threat.

The environment ministers of Japan, China and South Korea agreed in August to cooperate in addressing the arrival of the species in Japan.