SEOUL, Feb. 16 (UPI) -- South Korea immigration authorities are increasing border security at the main airport and a port facing China after various undocumented Chinese, Vietnamese nationals smuggled themselves into the country.
A new team is to tighten security checks at Incheon International Airport in response to at least two separate incidents of illegal border entry, Yonhap reported.
In January, a Chinese couple in their 30s posing as tourists escaped through the airport's third-floor departure hall while waiting for a transfer flight, and a few days later a Vietnamese national in his 20s managed to escape through automatic control doors before passing through immigration.
Seoul has not apprehended the individuals.
Local news network MBC reported a commercial port in Incheon is also under fire for lax security, after a Vietnamese sailor descended from a 5,000-ton cargo ship in the early dawn.
Four night guards at the docks were unable to apprehend the man after he cut his way through barbed wire that surrounds the pier.
Another sailor, a Chinese crew member, took off from a cargo ship that had docked at Dongkuk Steel Pier.
South Korea media reported security at commercial ports are lax, and there is not much regulation other than a requirement each company is required to station at least one security official for night duty.
South Korea's geography makes it difficult to reach for would-be illegal immigrants: The country is surrounded by sea on all three sides, and a heavily fortified border with North Korea makes it near-impossible to cross by foot.
But a recent arrest of more than 200 Thais, mostly women, shed some light on networks of human trafficking that could be growing in the country.
Local newspaper Munhwa Ilbo reported South Korea's Gyeonggi Police Agency arrested the women and their South Korean traffickers Tuesday, more than a year after the smuggling ring brought hundreds of women from Thailand to work at local "massage parlors."