Dozens more venomous fire ants have been found at Hakata port in Fukuoka Prefecture, while sightings have also been confirmed in Oita Prefecture, local officials said Tuesday.

At the Hakata port container yard where dozens of fire ants were spotted on Friday, some 50 more fire ants have been detected. With the discovery of fire ants in Nakatsu, Oita Prefecture, Tokyo and six prefectures have now been affected.

According to the Oita prefectural government, the fire ants were discovered in a container shipped from Kitakyushu east of Hakata.

At Hakata port, neither a queen ant nor ant larvae have been found, Fukuoka city officials said.

Fire ants, native to South America, are known for their sting, which can cause anaphylaxis, a severe allergic reaction that can lead to breathing problems and even death.

On Friday, some 40 fire ants were detected in a crack in the ground in the Hakata port's container yard. The ants found in the new investigation were detected in almost the same spot, according to the authorities.

Environment Minister Koichi Yamamoto told a news conference that his ministry will hold a meeting Thursday to discuss ways to prevent the ants from spreading and consider how they can be exterminated.

Yamamoto also said the ministry will quickly conduct inspections in areas within 2 kilometers of locations where fire ants have been found.

The ministry, in collaboration with the transport ministry, is also planning to conduct inspections at the country's 68 ports that regularly receive containers from China and other places where fire ants are found.

The government will provide these ports with poisonous feed by early August.