About 1 out of 6 young workers in South Korea were paid less than the country's minimum wage last year, a private think tank said Sunday, pointing to tough working conditions facing young adults already struggling with high unemployment.

According to the report by the Hyundai Research Institute, some 635,000 people aged between 15-29 were paid less than the minimum pay. The figure was much higher than the 449,000 people categorized in the same group for 2011.

The minimum pay in 2015 was set at 5,580 won ($4.9) per hour.

The ratio of the underpaid young adults compared with the total number of salaried workers in the same age group reached 17 percent in 2015 from 12.3 percent in 2011, the report showed.

The report is based on its analysis of economic activities-related data compiled by Statistics Korea.

The underpaid younger people earned a monthly average of 706,000 won last year, up from 636,000 won five years earlier. But the amount only represents 38.1 percent of the average pay of those earning more than the minimum.

The latest data underlined challenges for younger people in the workplace in terms of pay at a time when they are also struggling to find jobs amid frozen employment and a slowing economy.

Government data showed that the country's jobless rate stood at 4.3 percent in March, though it fell from the previous month's 4.9 percent. The jobless rate for people under 30 was much higher at 11.8 percent last month. (Yonhap)