Eggs from 23 more farms in South Korea has been found contaminated with harmful pesticides, authorities announced on Thursday.

The Ministry of Agriculture, Food and Rural Affairs said it has detected fipronil-contaminated eggs in five farms, while eggs from 18 other farms have been found to contain bifenthrin and other pesticides, reports Efe news.

The latest detection raised the number of contaminated poultry facilities in the country to 31.

Fipronil is a pesticide used to control ants, cockroaches and other insects and is prohibited in poultry farms, while Bifenthrin is used in various agricultural corps.

The ministry has undertaken inspections on all 1,239 poultry farms registered in the country after detecting fipronil on Tuesday in several facilities.

The government has also temporarily prohibited the sale of eggs at major retailers and supermarkets across the country to keep consumers safe from contaminated products.

South Korea has already restricted the sale of eggs produced in the country due to the 2016 outbreak of bird flu, forcing the Asian country to import eggs from countries such as Australia, New Zealand, Denmark, the Netherlands, Thailand and Spain.

There are currently no official reports on contaminated imported eggs in South Korea.

In early August, egg products from Belgium and Holland were reported to have been contaminated, while eggs from 17 other countries were also found to contain the substance.

According to experts, the pesticide fipronil possesses a very low risk of human intoxication, meaning that human would have to consume eggs contaminated with a maximum level of pesticide found in Belgium and the Netherlands throughout their lives to suffer its adverse effects.