File Photo: A United Nations vehicle is seen in Yemen. AFP
The Huthis raided the UN compound in the capital Sanaa last weekend, holding 20 staff, including 15 foreigners. Five Yemeni nationals were released on Sunday.
The rebels have detained UN staff and aid workers for years, accusing them of spying, but they have accelerated arrests since the start of the Gaza war.
"Earlier today, 12 UN international staff who were amongst those previously held in the UN compound in Yemen departed Sanaa on a UN Humanitarian Air Service flight," said a statement released by UN Secretary-General Antonio Gutteres's spokesperson.
Their destination was not revealed. The three remaining staff are now "free to move or travel", the UN said.
Among those detained was UNICEF's representative in Yemen, Peter Hawkins, a UN source and Huthi sources told AFP at the time.
The Huthis have frequently fired on Red Sea shipping and Israeli territory during the two-year the genocidal war on Gaza, in solidarity with the Palestinians.
Israel has launched numerous strikes, including a major attack in August that killed the Huthis's premier and nearly half of his cabinet.
Rebel leader Abdulmalik al-Huthi accused detained UN employees of having a hand in the attack, without giving evidence.
A total of 53 UN workers are still arbitrarily detained by the Huthis, according to the international body.
The rebels stormed UN offices in Sanaa on August 31, detaining more than 11 employees, it said.
A senior Huthi official told AFP the UN staff were suspected of spying for the United States and Israel.
In mid-September, the UN humanitarian coordinator in Yemen was transferred from Sanaa to Aden, the interim capital of the internationally recognised government.
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