The Houthi they announced today Monday that they dislocated one “US-Israeli spy cell”, a few days after they arrested about 12 United Nations agency workers.

The alleged core included former employees of the US embassy in Yemen, according to a televised announcement by Abdel Hakim Al Khaiwani, the Houthi intelligence chief.

“The American-Israeli spy cell has been spying and sabotaging official and unofficial institutions for decades, in favor of the enemy,” Al-Haiwani said. “Members of the cell and American officials took advantage of their position in the American embassy to carry out acts of sabotage. After the US embassy left Sana’a (…) members of the cell continued to implement their espionage agenda under the cover of international organizations and UN agencies,” he added.

Israeli and American officials declined to comment. The State Department did not immediately respond when asked for comment.

UN spokesman Stephane Dujarric said efforts were being made to free the 11 workers employed by five different UN agencies and the UN’s special envoy to Yemen.

Armed Houthi intelligence officers they also arrested three employees of the organization US-funded “National Democratic Institute” whose goal is to promote democracy, as well as three workers from a local humanitarian organization. The Houthi channel Al Masirah TV aired a series of videos purporting to show the confessions of some of those arrested. Reuters was unable to verify the videos.

The Houthis are holding about 20 Yemeni workers at the US embassy in Sana’a For three years. The embassy ceased operations in 2014.