Dozens of Thais have seemingly attempted illegal residency in South Korea after allegedly disguising themselves as supporters of a professional soccer team from Thailand, which held a match with a Korean team last Wednesday.

According to the Thai team, about 40 of more than 100 supporters that accompanied the players vanished after passing through immigration at Incheon International Airport. Considering the immigration office rejected the entry of 13 of the 100-plus supporters, the 40 runaways are assumed to have visited with the intention of staying in Korea illegally.

Statistics show the seriousness of the situation. According to the Justice Ministry, more than half of the 93,300 Thais residing in Korea were classified as illegally staying as of December 2015.

Further, it was the first time on record that foreign nationals had illegally gained entry to country under the guise of sports supporters, although the use of tourist visas to gain access to work here illegally is more common.

Currently, there are 1.9 million foreign nationals in Korea, accounting for 3.7 percent of the entire population. According to Justice Ministry figures, 11.3 percent of the total foreign population are in the country illegally.

Most people who are in the country illegally do low-paid, difficult jobs shunned by local workers. On the other hand, crimes committed by them in recent months have raised public concerns, prompting calls for strengthened measures to locate and deport them.

With more foreign nationals living in Korea than ever before, there has also been an increase in crimes involving foreign nationals, both as victims and perpetrators. Data from the Supreme Prosecutors’ Office showed the number such crimes has marked a 30 percent increase on-year over the past few years.

It is time for the nation to lay out a comprehensive plan to reduce the number of illegally residing migrants by tightening prescreening measures.

Apart from deportation, it is important the government takes measures to help immigrants who have been here for years with no criminal record to integrate into society more smoothly by offering them legitimate visas.

In that vein, state officials need to implement their plan as soon as possible. The Justice Ministry has said that it is considering screening foreign nationals before airlines issue boarding passes, and stepping up border controls for passengers who transfer at airports or enter Korea on visa-waiver schemes.

It is recommended the nation widen the scope of the employment permit system to prevent migrant workers from illegally staying in the country after their contracts expire. Under the current EPS, Korea selectively receives migrant workers from Asian countries who fill posts in labor-intensive industries.

Revisions involving expiry extensions would be beneficial to curb the rate of illegal stays and crimes resulting from poor living conditions.