The two Koreans were aboard a tugboat and a drilling rig that belong to the South Korean firm Woongjin Development Co. The third vessel was a Saudi Arabian tug boat chartered by a company from the United Arab Emirates.

The three vessels carrying the 16 crew departed for Jizan, Saudi Arabia, at 2:39 p.m. (Korean time) and are expected to arrive in two days, the ministry said.

The seizure took place in waters about 15 miles west of Yemen's Kamaran Island. The vessels were on the way to the Berbera port in Somalia after departing from Jizan, Saudi Arabia. After the seizure, the rebels took the boats to the Salif port in Hodeidah, Yemen.

A Houthi official later told Reuters they were willing to release them once they confirmed they were not related to the countries of aggression.

South Korean officials first learned of the seizure after one of the two Koreans sent a social media message to their company.

The government then deployed its anti-piracy Cheonghae Unit, which has been operating off the coast of Somalia, to back the rescue efforts.

The ministry said the government will work to strengthen safety measures for Korean citizens and ships to prevent such incidents from recurring in the future. (Yonhap)