DUBAI (Reuters) - The parties to over a year of civil war in Yemen have agreed to release all child prisoners they are holding, U.N. envoy to peace talks in Kuwait Ismail Ould Cheikh Ahmed said on his official Twitter account on Monday.

“The unconditional release of children was agreed, and the mechanics of the release of detainees in the coming days was addressed,” Ould Cheikh Ahmed wrote.

The Iran-allied Houthi group and Yemen’s Saudi-backed government in exile are trying to reach a peace agreement in negotiations aimed at ending the war that has killed at least 6,200 people and caused a humanitarian crisis in the Arabian Peninsula’s poorest country.

There was no immediate comment from either side’s peace delegation in Kuwait on the U.N. envoy’s announcement.

It is clear how many child prisoners are being held, but Yemeni political sources say that the Houthis and the government submitted in late May a list of almost 7,000 names of prisoners they say are being held by the other side.

Human Rights Watch said this month that both sides in the conflict were deploying child soldiers and UNICEF reported that 900 children have been killed and 1,300 wounded during the conflict in 2015.

The U.N. has struggled to encourage a prisoner release in Yemen coinciding with the Muslim holy month of Ramadan, which began on Monday, and over a month of negotiations have produced few concrete results.