Reports from western Yemen say Iranian-backed Huthi rebels have begun withdrawing from two of the three Red Sea port facilities they've vowed to evacuate under a peace deal negotiated in Stockholm in December.
The Yemeni government, however, accused the rebels of "staging a new ploy" by faking the withdrawal.
Provincial Governor Al-Hasan Taher told AFP the rebels were handing the ports "to themselves without any monitoring by the United Nations and the government side."
The United Nations on May 11 said it was monitoring the withdrawal from the Red Sea port facilities of Saleef and Ras Isa, which they have held since 2014.
The UN monitors plan to report to the Security Council about the situation on May 15.
The UN says the Huthi rebels announced late on May 10 that they would unilaterally redeploy their forces out of three Red Sea port facilities over four days beginning on May 11 – potentially opening the way for the delivery of humanitarian aid needed to prevent a famine that threatens millions of people.
Under the redeployment pledge, Huthi militants said they also would move out of Yemen's main Red Sea ports of Hodeidah by the end of the day on May 14.
The head of the UN's Redeployment Coordination Committee called the pledge "the first practical step on the ground" since the conclusion of the Stockholm agreement.
Under that agreement, pro-government forces in Yemen also are expected to leave positions around the outskirts of Hodeidah during the initial redeployment before a second phase in which both sides withdraw their troops further.
But the UN's statement did not specifically mention any reciprocal redeployment by the pro-government forces, which have the support of a military coalition led by Saudi Arabia and the United Arab Emirates.
The coalition alleges that the Huthis have been using Hodeidah, Yemen's principal Red Sea port, as a landing point to smuggle weapons supplied by Iran. The Huthis deny those charges.
The UN committee's chairman, Lieutenant General Michael Lollesgaard of Denmark, said the Huthi redeployment must be followed by "the committed, transparent, and sustained actions of the parties to fully deliver on their obligations."