Houthis admit to hijacking South Korean and Saudi vessels
The incident follows a lull in Houthi attacks on Saudi Arabia as one Riyadh official said the kingdom had established an "open channel" with the rebels in a bid to end the four-year conflict.
The Houthis acknowledged they had seized three ships, including a Saudi one, in the Red Sea a few miles off Uqban island, west of the rebel-held capital Sanaa.
Seoul's foreign ministry said a South Korean dredger was being towed by one Korean and one Saudi-flagged tug when they were seized by the Houthis.
Yemen in Focus: Pirates of the Arabian? Houthis seize Saudi vessel in latest peace blunder
It added that a total of 16 crew, two of them South Korean, had been taken to the Red Sea port of Saleef, where they were being held by the rebels.
"All of our citizens... are healthy and safe," ministry officials said in a statement. "We are doing our very best for the early release of our citizens."
Seoul has sent the South Korean navy ship Cheonghae, which had been on anti-piracy standby off the coast of Oman, to waters near where the incident took place.
The Saudi-led military coalition backing Yemen's internationallyp-recognised government accused the rebels of "hijacking" the Rabigh-3, which a global tracking website described as a Saudi-flagged vessel.
A Saudi cabinet session, chaired by King Salman, also condemned the rebels on Tuesday, saying such incidents pose a threat to the freedom of international navigation and trade.
The rebels sought to defend their action, saying in a statement carried by their Al-Masirah television channel that the three ships were seized off Uqban Island after they entered "territorial waters without prior notice".
The ships were taken to Saleef, it added, without disclosing the nationalities or number of crew members.
The Houthi rebels have been fighting the government and its allies for more than four years in a war that has pushed the country to the brink of famine.
A year after the Houthis seized Sanaa, Saudi Arabia, the UAE and their allies intervened in the conflict in support of President Abedrabbo Mansour Hadi.
Since 2015, tens of thousands of people - most of them civilians - have been killed in a conflict that has triggered what the United Nations has described as the world's worst humanitarian crisis.