Yemen's Iran-backed Houthi rebels has released three vessels and 16 people it had seized, South Korea's foreign ministry and a Houthi military source in Yemen said on Wednesday.
The rebels said the vessels were 5 kilometres off the Yemeni island of Uqban, adding its coastguard has forced the vessels to head to Salif port in the Red Sea province of Hodeidah.
The Houthis have in the past targeted oil tankers and military ships belonging to Saudi Arabia and its partners in the coalition fighting in Yemen’s war since 2015.
Of the vessels freed on Tuesday, two were South Korean and one was Saudi Arabia-flagged, the South Korean foreign ministry said in a statement, adding that the families of two South Koreans among the crew had been notified.
"The three ships were released after the necessary legal measures," the Houthi military source in Yemen told Reuters, adding that all crew were also released.
On Twitter, Hussein al-Azzi, the Houthi deputy foreign minister, said the release resulted from friendly ties between Seoul and Sanaa, the Yemeni capital the Houthis overran in 2014.
A Houthi investigation found the ships had entered Yemeni waters due to bad weather, he added. Earlier, the Houthi coast guard had said the vessels entered Yemeni waters without permission.
The Houthi movement had said it would release the captured vessels if they proved to be South Korean, after it seized a rig being towed by a Saudi-flagged tugboat in the southern part of the Red Sea.
The Saudi-led coalition said the seized vessels included a Korean drilling rig and the Saudi tug, the Rabigh 3, which were captured by armed Houthi fighters who attacked from two boats.
When the boats were originally seized, Coaltion spokesman Col Turki Al Malki said the action threatened vital shipping routes in the Bab Al Mandeb, the strait used for oil shipments from the Gulf to Europe, and goods from Asia.
The Arab Coalition intervened in Yemen in March 2015 against the Houthis after they ousted the government from power in Sanaa.
Houthi forces have been driven away from most of Yemen's coast during the conflict, but still hold Hodeidah, the country's biggest Red Sea port and the base of the group's navy.
The United Nations says the Houthis attacked two oil tankers last year in the Bab al-Mandeb strait at the southern mouth of the Red Sea, as well as a vessel carrying wheat to Yemen.