Two Vietnamese workers were killed and two others injured in an explosion of a chemical plant in Wonju City in South Korea on Saturday.

The explosion happened in the morning after a short circuit while workers were welding a tank filled with chemicals. Two Vietnamese workers, Chu Van Duong, 31, and Tang Van Khanh, 28, were killed in the blast, VN Express reported.

Two other Vietnamese workers, Do Quoc Hung, 31, and Vuong Dac Khai, 21, were injured and suffered extensive burns. They were being treated at a local hospital.

The Overseas Labor Center under Vietnam’s labor ministry informed the victims’ families and assisted them with the paperwork to arrange the repatriation of the bodies of the two workers.

As of June 2018, there were more than 45,000 Vietnamese workers in South Korea. The country is one of the largest labor export markets for Vietnam.