More than 110 workers at a factory east of Seoul have tested positive for the new coronavirus, officials said Wednesday, becoming the latest in a recent string of mass infections at industrial workplaces.

According to the municipal officials of Namyangju, Gyeonggi Province, as many as 114 employees from a single plastic manufacturing plant in the city's Jingwan General Industrial Complex, about 40 kilometers from Seoul, have been diagnosed with COVID-19.

The newest cluster of factory worker infections has been confirmed after health authorities conducted coronavirus tests on all of the plastic plant's 177 workers, including 145 foreign nationals, they said.

Foreign nationals accounted for 105 of the infected workers and most of them lived and dined together at a company dormitory.

The tests on all of the plant's workers came after a foreign employee tested positive for COVID-19 at a hospital in central Seoul last Saturday after displaying fever symptoms.

The officials said 113 more workers were found to be infected Wednesday morning and five others will be re-tested soon due to indecisive results.

They raised fears of community transmissions as many of the infected foreign workers had meetings outside of the plant during last week's Lunar New Year holiday.

The municipality of Namyangju said it has opened a temporary testing station at the industrial complex to administer coronavirus tests to all 1,200-odd workers at its 59 factories, mostly in the textile, pulp, metal processing and electrical equipment businesses.

The city government also said it was looking into the detailed travel routes of the infected workers and local people who may have come into contact with them during the holiday.

Meanwhile, the number of confirmed cases tied to a separate coronavirus cluster from a boiler factory in central South Korea has risen to 122, the relevant local government said.

The tally from the virus cluster of Kiturami Boiler's plant in Asan, South Chungcheong Province, has been updated after 22 more factory workers were confirmed to be infected.

The cases include 99 plant workers and 17 family members and acquaintances, Asan officials said, noting 24 of them are foreign employees and their acquaintances.

The officials speculate that the virus may have spread among more than 100 workers through fan heaters in one of the boiler plant's poorly ventilated buildings.

They also raised fears of massive secondary transmissions of the virus by the infected Kiturami workers who visited their hometowns during the Lunar New Year holiday.

Indeed, several families and relatives of the infected Kiturami workers were found to have contracted the virus in Daegu and Cheongdo, both in southeastern South Korea, and Siheung, just south of Seoul. (Yonhap)