Yemen’s Houthi movement’s lead negotiator said peace negotiations with Saudi Arabia had made progress and that more meetings would be held to iron out lingering issues.

The end of talks in Yemen’s capital Sanaa was followed by an announcement from the International Committee of the Red Cross on Friday that the warring sides had initiated an exchange of roughly 900 detainees.

Saudi Arabia, which leads a coalition that has been battling the Iranian-aligned Houthis since 2015, is seeking a permanent ceasefire deal to end its military involvement in a war that has killed tens of thousands of people and left millions hungry.

Houthi chief negotiator Mohammed Abdulsalam said on Friday the negotiations with envoys from Saudi Arabia and Oman, which is facilitating the talks, had been “serious and positive”.

“There was advancement on some issues with the hope of continuing studying outstanding issues at another time,” he said in a Twitter post, without elaborating.

The visit by the Saudi delegation, which departed Sanaa on Thursday according to two Yemeni sources, signalled movement to build on an expired U.N.-brokered truce and followed last month’s deal between Saudi Arabia and Iran to restore ties.

Sources have told Reuters that the Saudi-Houthi talks were focused on a ceasefire, full reopening of Houthi-controlled ports and Sanaa airport, payment of public sector wages, rebuilding efforts, and withdrawal of foreign forces from Yemen.