Two diplomats familiar with the matter said that an investigation by a team of United Nations experts concluded that the Houthis in Yemen carried out an attack on December 30 on Aden airport that killed at least 22, upon the arrival of members of the internationally recognized Yemeni government.
The diplomats said that the experts submitted their report to the United Nations Committee that oversees sanctions related to Yemen during consultations behind closed doors on Friday, but Russia prevented it from being published on a wider scale.
The two diplomats requested that their names not be published due to the sensitivity of the matter.
The Houthis denied responsibility for the attack when it happened.
The diplomats did not explain why Russia was preventing the publication of the results, and the Russian mission to the United Nations did not respond to a request for comment.
The report comes at a sensitive time for the new US president, Joe Biden, as his administration and the United Nations are pressuring the Houthis to accept a peace initiative that includes a ceasefire.
Saudi Arabia and the Yemeni government supported the initiative, but the Houthis say it is not a new offering.