UNITED NATIONS, Oct. 22 (Xinhua) -- Twelve UN international staff who were among those previously held in a UN compound in Yemen departed Sanaa on a UN Humanitarian Air Service flight on Wednesday, according to the Office of the Spokesperson for the UN Secretary-General.

In a note to correspondents, the office said that three other international staff who were detained in the compound are free to move or travel.

"Currently, 53 UN colleagues remain arbitrarily detained by the de facto authorities" in Yemen, in addition to personnel from non-governmental and civil society organizations as well as from diplomatic missions, the note said.

The United Nations, at all levels, continues to be seized with the matter and is in constant contact with the relevant authorities in Sanaa and with concerned UN member states and partners to secure their release, it said.

"We renew the Secretary-General's call for their immediate and unconditional release," it added.

On Saturday, a Yemeni security official told Xinhua that Houthi forces stormed the UN compound, seized employees' mobile phones, and interrogated staff members. ■