The heads of the UN agencies and aid organisations termed the detention of their staffers to be "unprecedented -- not only in Yemen but globally".
The chiefs of six United Nations agencies and three international humanitarian organisations on Thursday jointly urged Yemen's Houthi rebels to immediately release 17 members of their staff, who along with several others, were recently held by the secretive rebel group.
The appeal was backed by statements from several nations and the European Union ahead of session of the UN Security Council on Yemen. Hans Grundberg, UN special envoy said that the Houthis were holding all those detained in the crackdown, without any communication.
Notably, the Houthi Rebels last week had detained at least 9 Yemeni employees of the UN agencies over unspecific reasons amid the rising financial pressure and the airstrikes on the group from a US-led coalition.
The Iran-backed group on Monday had said that it arrested members of an "American-Israeli spy network".
Head of the Houthis' intelligence agency, Major General Abdulhakim al-Khayewani, had informed of the arrests, saying that the spy network first operated out of the US embassy in Yemeni capital of Sanaa.
After its closure in 2015 following the takeover of Sanaa and northern Yemen by the Houthis, he said, the network continued "their subversive agenda under the cover of international and UN organisations".
However, the Major General did not clarify as to how many were actually arrested. Reportedly, officials of the rebel group released a purported video of alleged confessions by 10 Yemen nationals, many of whom they claimed were hired by the US Embassy.
The video did not include any of the UN staffers who were arrested, as per a report from The Associated Press.
Meanwhile, the heads of the UN agencies and international organisations termed the detention of their staffers to be "unprecedented -- not only in Yemen but globally".
They also urged the Houthi rebels to reveal the exact details of where the UN employees were detained. Citing international humanitarian law -- which bounds all parties involved in the conflict to respect and protect humanitarian personnel -- the heads asked for immediate access.
The joint statement from the UN agencies and the aid organisations said, "The targeting of humanitarian, human rights, and development workers in Yemen must stop," adding that "all those detained must be immediately released."
The statement, which was read by British Ambassador Barbara Woodward outside the UNSC chamber, sternly condemned the detentions that have taken place since June 7, demanding the release of those held. It also expressed critical concern over the increasing deterioration of humanitarian conditions in Yemen.
The countries also addressed the concern over the delivering of humanitarian aid into Yemen and asked for uninterrupted access for all humanitarian workers.
A civil war has been going on between Yemen's government in exile in Aden and the Houthi rebels since 2014, when they took control of Sanaa and northern Yemeni regions.
The special UN envoy, Grundberg, who has been engaged in negotiating an end to the conflict, also appealed to not only release the 13 recently detained UN employees, but for four other UN staffers who had been held incommunicado -- two since 2021 and other two since 2023.
“The United Nations is present to serve Yemenis,” he told the UNSC, adding that "such arbitrary detentions are not the expected signal of an actor who is seeking a mediated solution to the conflict."
The detentions came amid the continuous targetting of shipping across the Red Sea corridor at the hands of the Houthi rebels over Israel's war on Gaza. It has also been tackling dissent at home, including the capital punishment to 45 people.
Reiterating the United Nations' stance against the death penalty, Grundberg had expressed concern over the death sentences to the 45 people.
However, the reason behind the latest detentions continue to be unknown.
Amid the release request of the UN staffers, the US on Thursday said that the Houthis launched two anti-ship cruise missiles and struck a commercial ship in the Gulf of Aden off Yemen, setting a fire and critically injuring one civilian mariner.
US Central Command said the M/V Verbena was still on fire when the mariner was being flown by a US helicopter based on the USS Philippine Sea to another nearby ship for treatment.
USCC, in a statement, said that Verbena is a Palaun-flagged, Ukraine-owned and Polish-operated bulk cargo carrier that was on its way to Italy carrying wood. It had been docked at Malaysia earlier.
"M/V Verbena reported damage and subsequent fires on board. The crew continues to fight the fire. One civilian mariner was severely injured during the attack," USCC statement read.
It said that the continued reckless behaviour on the part of the Iran-backed secretive group is a threat to regional stability, adding that it endangers the lives of several mariners across the Gulf of Aden and the Red Sea.
"The Houthis claim to be acting on behalf of Palestinians in Gaza and yet they are targeting and threatening the lives of third country nationals who have nothing to do with the conflict in Gaza," it added.
"U.S. CENTCOM will continue to act with partners to hold the Houthis accountable and degrade their military capabilities," the statement read.
(With AP inputs)