More than 20 miners were found to have been killed or injured at mines across the nation this year so far, government data shows. 

The Ministry of Trade, Industry and Energy on Tuesday said that the number of mines under operation stood at 325 last year, marking a gradual decline from 414 in 2012. 

The number of miners in the country also declined from seven-thousand-491 to five-thousand-590 during the same period. 

According to the ministry, 59 miners lost their lives in industrial accidents since 2012, while 207 others sustained serious injuries. Among them, four died on the job in the January through September period this year and 17 were critically wounded. 

The data was revealed as the government plans to check up on safety measures at old mines after two workers trapped in a collapsed zinc mine in Bonghwa, North Gyeongsang Province were safely rescued last Friday after more than nine days below ground.