(Beirut) – Houthi officials in Yemen confiscated the passport of a prominent human rights advocate on March 4, 2016. The Houthis should immediately end the travel ban on Abdulrasheed al-Faqih, executive director of the Mwatana Organization for Human Rights, the country’s leading independent documentation group.

The Houthis should stop interfering with the work of Yemen’s human rights advocates and organizations, which is being carried out with increasing difficulty.

“Cracking down on human rights workers by taking their passports speaks volumes about human rights under the Houthis,” said Joe Stork, deputy Middle East director. Abusive actions like these will only undercut the Houthis’ credibility in future peace talks.”

Al-Faqih told Human Rights Watch that he landed at Yemen’s Sanaa airport at 10:30 a.m. on March 4, after attending an international media conference in Amman, Jordan. Houthi officials at the airport questioned him for more than 20 minutes about his participation in the conference and about an older visa for Turkey on his passport. Without providing a reason, they kept his passport and told him to leave the airport. Without his passport, al-Faqih cannot travel outside of the country.

This is the second travel ban the Houthis have imposed on a rights advocate in the past six months. Since October 2015, they have prevented Shafiqa al-Wahsh, director of the semi-governmental Women’s National Committee of Yemen, from traveling abroad to participate in dialogues about women’s roles in the peace negotiations.

The International Covenant on Civil and Political Rights, to which Yemen is a party, states that, “everyone shall be free to leave any country,” including their own. Any restrictions to this right must be provided by law and necessary for national security or other grounds, but they “must not nullify the principle of liberty of movement” and must be consistent with other rights. The United Nations Human Rights Committee has said that any legal restrictions “should use precise criteria and may not confer unfettered discretion.”

The Houthis, an armed group from northern Yemen, gained control of the capital, Sanaa, and other areas in September 2014, ultimately causing President Abdu Rabu Masour Hadi and his cabinet to flee to Saudi Arabia. On March 26, 2015, a Saudi-led coalition of nine Arab countries began an aerial campaign against the Houthi and allied forces in Yemen.

Since taking control of the capital, the Houthis have harassed al-Faqih and his wife, Radhya al-Mutwakel, president of the Mwatana Organization. On August 9, Houthi forces arrested al-Faqih and detained him at al-Judairi police station, where guards interrogated him about work he was doing to petition for the release of women being held for their affiliation with the opposition Islah party. The guards beat him and detained him for five hours, but then released him without charge.

On September 19, Houthi forces arrested both al-Faqih and his wife because of their work documenting continued Houthi human rights violations, including arbitrary detention and enforced disappearances. They released al-Mutwakel promptly but held her husband for 10 hours, then released him without charge.

Over the last year, the Houthis have shut down human rights and other nongovernmental organizations, and arbitrarily arrested members of these groups. Members of three nongovernmental organizations told Human Rights Watch that Houthi gunmen raided and shut down their offices in April and have prevented them from reopening. Human Rights Watch also documented the Houthis’ enforced disappearance of Abd al-Kader al-Guneid, a physician and human rights activist, on August 5. The Houthis have yet to provide his family with any information about his whereabouts or situation.

The Houthis have arbitrarily or abusively detained at least 35 people from August 2014 through October 2015, seven of whom had been forcibly disappeared, Human Rights Watch said.

“Yemeni human rights advocates can play a crucial role in any future peace processes if their voices are heard,” Stork said. “The Houthis should be encouraging rights defenders to carry out their work, not unlawfully interfering in their activities.”