According to agency's sources, the relatives of the four victims arrived at Incheon airport on Monday morning and carried out with them the urns containing the ashes of their loved ones.
Preparations for taking the boat from the river are expected to be finished by the end of the day, while the actual operation may begin in the evening.
According to Yonhap, the passengers were taking a tour across six countries in Eastern Europe. According to most recent reports, 19 South Koreans were killed and seven more are still missing. South Korean President Moon Jae-in has instructed the government to use all possible means to find those who went missing after the accident.