The US reiterated on Thursday its concern over the Iran-backed Houthi militia’s continued obstruction of the peace process in Yemen and harassment American and UN-employed local Yemeni staff.

“If they are serious about peace and upholding international norms, they will release our colleagues immediately,” said Samantha Power, administrator of the US Agency for International Development.

The UN Security Council had condemned in the strongest terms the Houthis’ seizure and intrusion into a compound that was formerly used to house the US embassy in Sanaa, when dozens of local employees were detained.

Power was speaking a day after US ambassador to the UN Linda Thomas-Greenfield issued a similar statement saying the Houthi militia is continuing these actions despite condemnation from the Security Council.

“The Houthis must immediately cease threats, release unharmed those detained, vacate the compound, return seized US property, and cease their threats against our employees and their families.” she said during a Security Council briefing on Yemen on Wednesday.

UNESCO and the UN High Commissioner for Human Rights on Dec. 28 said they continued to be deeply concerned for the well-being of two of their staff members who were detained in early November in Sanaa. 

No communication from the UN has been possible with the staff members since that time.

“Although the two staff members remain in custody, the UN has not received information about the grounds or legal basis for their detention, or their current status, despite earlier assurances by the Ansar Allah movement (who are also called Houthis) of their immediate release,” the two UN bodies said in a joint statement.

“OHCHR and UNESCO recall the privileges and immunities accorded to staff of the UN system under international law, which are essential to the proper discharge of their official functions, and call for the staff members’ immediate release without any further delays,” they added.