The Houthis in Yemen have detained UN staff and aid workers.

At least 11 United Nations personnel have been detained by Yemen's Houthi group, according to UN spokesperson Stephane Dujarric, who urged for their immediate and unconditional release.

Dujarric stated on Friday that the UN is seeking clarification from the Houthis regarding the reasons behind the detention of the Yemeni employees, who include two women and nine men working for five different UN agencies and the UN envoy for Yemen.

"We are exploring all available channels to ensure the swift and unconditional release of all individuals, and we also seek access to them," Dujarric remarked, emphasizing the UN's efforts.

Additionally, armed Houthi intelligence officers reportedly detained three employees of the US-funded pro-democracy group National Democratic Institute (NDI) and three employees of a local human rights organization in a series of raids, according to three officials of Yemen’s internationally recognized government who spoke to Reuters on Friday.

Human Rights Watch (HRW) condemned these detentions, stating that the Houthi group's refusal to disclose the whereabouts of the detained individuals could constitute enforced disappearance under international law.

Niku Jafarnia, Yemen and Bahrain researcher at HRW, emphasized the urgent need for the release of the detained individuals and urged the Houthis to cease arbitrary detentions, which undermine humanitarian and human rights efforts in Yemen.

The motives behind these detentions remain unclear. However, they occur amidst heightened tensions and uncertainties regarding the sustainability of the fragile peace between the Houthis and the internationally recognized government.

Recent developments, such as the government's demand for banks to relocate their headquarters to Aden, could exacerbate economic pressure on Houthi-controlled areas, as they control the capital Sanaa and claim legitimacy over the country.

Reports suggest that Washington is considering blocking significant parts of a United Nations peace plan adopted by the warring parties in Yemen unless the Houthis halt their attacks on international shipping, which have intensified since November.

Yemen's Saudi-backed government's Information Minister Moammar al-Eryani denounced the detentions as a blatant violation of international laws and conventions, labeling them as an unprecedented escalation.

Former employees of the United States Embassy in Sanaa, which closed in 2015, have also reportedly been detained and held by the Houthis.