Amnesty International on Wednesday called for the release of all detainees in Yemen and that the fate of those forcibly disappeared be disclosed.
The organization said in a tweet on its Twitter account: "Yesterday, the Houthi group released 290 detainees, including 42 survivors of a coalition airstrike that killed nearly 130 detainees in Dhamar, according to the International Committee of the Red Cross."
The organization added: "We welcome this decision and renew our call for the release of all detainees and the disclosure of the fate of the disappeared."
The International Committee of the Red Cross (ICRC) announced last Monday that the Houthis (Ansar Allah) released 290 prisoners in a unilateral operation.
In early September, the Houthi group said the Saudi-led Arab coalition warplanes to support of legitimacy in Yemen launched air raids on a prisoner site in the city of Dhamar, killing more than 150 prisoners and wounding 50 other.
The coalition then said it had evidence (unspecified) to prove that the site it bombed in Dhamar was a "military target" and not a prisoner site.
The file of the prisoners of the most important thorny files, included in the "Stockholm" agreement concluded in mid-December last year between the "legitimate" government and the Houthis under the auspices of the United Nations.
The parties agreed to exchange lists of about 15,000 prisoners.
However, the actual implementation of the agreement remains stalled, as is the ceasefire agreement, the redeployment of forces from Hodeida city and its ports, and understandings about Taiz, amid mutual accusations of obstructing the implementation, which was due to be completed in January.
Yemen conflict has triggered what the UN calls the world's worst humanitarian crisis, with most of the population in need for a type of humanitarian aid and immediate protection, including 14 million people risking famine and some 1.8 million children suffering malnutrition.