"The Houthis must immediately release all Yemeni US employees," Blinken said in a statement posted on the State Department's website.
He added that the Houthis are required to return the property of the embassy and stop threats.
According to him, this detention is a violation of diplomatic norms.
On November 8, US Special Envoy Tim Landerking and US Charge d'Affaires to Yemen Katie Westley visited the Yemeni city of Aden.