Almost a month of prisoner exchange talks between Yemeni officials and Houthi rebel representatives in Amman ended on Sunday without results, a UN official said. UN special envoy to Yemen Martin Griffiths said he was “disappointed” the talks did not end with the release of 300 prisoners, for which the two sides have been negotiating at meetings in Jordan’s capital. Thousands of Yemenis are in jail or have vanished in the seven-year civil war, although more than 1,000 prisoners were released in November last year after a deal in Montreux, Switzerland. Mr Griffiths, whose office is in Amman, urged the two sides to remain part of a prisoner exchange process supervised by the UN and the Red Cross, and to “expand the arrangements to release more detainees soon”. “I reiterate my call for the unconditional release of all sick, wounded, elderly and children detainees, as well as detained civilians, including women and journalists,” he said. The main conflict is between the internationally recognised Yemeni government and other forces in a Saudi-led coalition against the Iran-backed Houthis, who overran the capital, Sanaa, in 2014. The focus of the talks was on journalists and very sick people, as well as senior pro-government figures captured by the Houthis. Among them are Naser Mansur Hadi, who is the brother of Yemeni President Abdrabu Mansur Hadi, and former defence minister Brig Mahmoud Al Subaihi. There was no immediate reaction from either side. Abdel Qader Al Murtada, head of the Houthi delegation, said he had hoped before the talks for “success for this round and the release of the largest number of prisoners from all sides”. Several prisoner swaps have concluded, with the Montreux deal the first under the 2018 Stockholm peace agreement. Both sides had submitted lists with the names of 15,000 detainees they wanted freed and accused each other of delays.