Rebel militants are kidnapping and torturing protesters and people deemed as opponents in Yemen, according to the human rights organisation Amnesty International.
In a new report, the NGO details how the group has arrested peaceful protesters and taken them to secret locations where they were tortured.
Ali Taher al-Faqih and Abelaji al-Subari were kidnapped from a peaceful protest in the Yemeni capital of Sanaa on February 11, Amnesty reported, along with Salah Awdh al-Bashri.
The three men were arrested, abducted and tortured in a basement, which led to the death of Bashri. The other two men survived the ordeal and were released on the evening of February 13.
"They tied my hands behind my back, bound my feet, made me lie face down on a sort of narrow table and started beating me with some sort of baton on the buttocks," Faqih told Amnesty on February 15.
"The beating went on for a long time, maybe a couple of hours. The pain was excruciating. They kept telling me to confess. When they finally stopped beating me I was only semi-conscious. They had to help me up."
The well-armed militia seized control of the capital Sanaa last September and is in de-facto control of the northern Saada province.
The group recently issued a constitutional declaration in which they established a transitional presidential council that they said would last for two years. Its opponents have described it as a coup.
Amnesty has spoken to a number of other individual activists who have reported that they have been tortured by the Houthis this year.
"The safety of all those who dare to speak out against the Houthi rule is on the line," said Amnesty's Donatella Rovera.
"The Houthis must put an immediate stop to their illegal tactics or arbitrary detentions, torture and other ill-treatment," she said in a statement.