the Russian foreign ministry

Twenty-four Russian nationals were detained on Friday upon arrival at Seoul's Incheon International Airport, the Russian foreign ministry said in a statement carried by Tass news agency. 
The South Korean authorities said the Russian citizens were detained for "violation of migration laws," the ministry said, adding that "the Russia embassy will help settle the situation and will offer all necessary assistance to the Russian nationals." "The local authorities might have suspected these people of being labor migrants seeking employment in South Korea who have come here as visa-free tourists," a spokesman for the Russian embassy in South Korea told TASS, adding that this is the most typical reason for entry denial.

Source: QNA