UPDATE 1-Medical flights to start from Yemen's Sanaa in diplomatic breakthrough

Flights carrying patients in need of urgent medical attention will begin from the Yemeni capital Sanaa on Monday, aid and diplomatic sources said, a long-sought confidence-building measure in diplomatic efforts to end the five-year war.

The United Nations and World Health Organization will supervise patient transfers and flights which are expected to go to Amman in Jordan and Cairo in Egypt, aid organization the Norwegian Refugee Council (NRC) said. "It is hoped these flights will enable the opening of regular medical 'bridge' flights for sick patients," NRC said. "There is no justification for punishing very sick civilians by blocking them from accessing medical treatment."

Yemen has been mired in conflict since the Iran-aligned Houthis ousted the government of President Abd Rabbu Mansour Hadi from Sanaa in late 2014. A Saudi-led military coalition intervened in 2015 to try to restore Hadi. Although the Houthis control Sanaa airport, access is restricted by the coalition, which controls the air space. The airport has been closed to civilian flights since 2015 and only U.N. planes can land there currently, meaning thousands of people needing to travel abroad for medical attention have not been able to leave.

Re-opening the airport has been a key aim of U.N.-led peace talks and a key demand of the Houthi administration. The medical flights were the result of months of negotiations and the project had received an "extraordinary" amount of diplomatic support, U.N. Yemen Envoy Martin Griffiths said in an address to the Security Council last month.

The United Nations has been trying to re-launch political negotiations to end the war. Separately, Riyadh has been holding informal talks with the Houthis since late September about de-escalation. Griffiths held last-minute talks with Houthi authorities on Sunday regarding the plans, a diplomatic source said.

The source said around 60 patients and relatives are expected to leave on flights this week and the NRC said seven patients are expected on the first flight. Mohammed Ali al-Houthi, head of the Houthis' Supreme Revolutionary Committee, said 32,000 people were registered on medical evacuation lists.