The Houthi rebels in Yemen stormed the headquarters of the United Nations’ Human Rights Office in the capital, Sanaa, seizing documents, furniture, and vehicles, a senior U.N. official said Tuesday.

This seizure is the latest escalation in the Houthis’ crackdown on individuals working with the U.N., aid agencies, and foreign embassies. The crackdown coincides with the Iranian-backed rebels’ targeting of shipping throughout the Red Sea corridor in response to the Israel-Hamas conflict.

The rebels took control of the U.N. Human Rights Office’s premises in Sanaa on August 3, forcing U.N. Yemeni workers to relinquish their belongings, including documents, furniture, and vehicles, according to U.N. Human Rights Chief Volker Türk’s statement.

“Ansar Allah forces must leave the premises and return all assets and belongings immediately,” Türk said, referring to the official name of the Houthis.

A spokesman for the Houthis didn’t respond to phone calls and messages seeking comment.

The U.N. said it had suspended the office’s operations in Sanaa and other Yemeni areas controlled by the Houthis following a crackdown campaign in June. However, it continues to operate in the parts of Yemen controlled by the internationally recognized government.

In June, the Houthis detained more than 60 individuals working with the U.N. and other NGOs, according to the U.N. Human Rights Office. Among the detainees were six workers with the Human Rights Office, who joined two of their colleagues previously detained by the Houthis in November 2021 and August 2023, the office said.

Days after the arrest campaign, the rebels claimed to have apprehended members of what they called an “American-Israeli spy network.”

The Houthis released what they claimed were videotaped confessions by 10 Yemenis, several of whom stated they were recruited by the U.S. Embassy in Yemen. The U.N. Human Rights Office reported that one of its detained staff members appeared in a video where he was coerced into confessing to allegations, including espionage.

The Houthis’ claims couldn’t be independently verified.

The Houthis have been engaged in a civil war with Yemen’s internationally recognized government, backed by a Saudi-led coalition, since 2014, when they seized control of Sanaa and most of the north.

The war in Yemen has resulted in the deaths of over 150,000 people, including fighters and civilians, and has created one of the world’s worst humanitarian disasters, leading to the deaths of tens of thousands more.

The rebels have imprisoned thousands of people during the war. In recent months, they have intensified their crackdown on dissent at home, including recently sentencing 44 people to death.