SANAA: Yemen's Houthi group announced that they have arrested several Yemeni nationals accused of spying for Israel in the capital Sanaa.

In a statement, the Houthis claimed the detainees were collaborating with the Israeli foreign intelligence service, Mossad, through a Saudi-based joint operation room that allegedly involved three foreign intelligence agencies -- those of Israel, the United States, and Saudi Arabia, Xinhua news agency reported.

They also claimed that the arrested were trained to write intelligence reports, spy on civilian and military locations, and monitor the movements of the group's officials.

The Houthis did not tell how many people they have arrested, nor provide evidence of the alleged espionage accusations.

The statement said "confessions" of the arrested were to be broadcast later in the day on its official satellite television channel, al-Masirah.

According to a source close to the group, most of the newly arrested are employees with the United Nations aid agencies, including the World Food Program (WFP), the World Health Organization (WHO), and the UN Children's Fund (UNICEF).

This came weeks after the UN body secured the release of 20 foreign aid workers through a mediation of Iran and Oman, and flew them out of Yemen, according to a UN statement at that time.

UN Special Envoy to Yemen Hans Grundberg said in a recent statement that at least 53 UN aid employees of Yemeni nationals remain in Houthi prisons, as well as dozens of other Yemeni employees working with non-governmental organizations and those who had worked with foreign diplomatic missions.

The arrests came after Israeli airstrikes on Sanaa in August killed a dozen members of the Houthi-run cabinet, as well as the Houthi military chief of staff, Mohammed Abdulkarim Al-Ghamari.

The Houthis have tightened security measures in Sanaa and declared general mobilization after Israeli Prime Minister Benjamin Netanyahu declared in a televised speech last week that the Houthis pose a threat to the existence of Israel and vowed to eliminate the group.

The Houthis, which control much of northwestern Yemen, including Sanaa, had launched dozens of ballistic missiles and bomb-laden drones toward Israeli air and sea ports, as well as targeting ships linked to Israel in the Red Sea to show solidarity with Palestinians since the Gaza war broke out in October 2023. The group has stopped its attacks since the Gaza ceasefire went into force last month.