Armed Yemeni tribesmen from the Popular Resistance Committees, supporting forces loyal to Yemen's Saudi-backed President Abedrabbo Mansour Hadi, fire as they hold a position in the area of Sirwah, west of Marib city, on December 18, 2015
United Nations (United States) (AFP) - The United Nations special envoy for the conflict in Yemen warned UN ambassadors on Tuesday that a fledgling peace process was hanging by a thread.
At the weekend Yemen's Saudi-backed government and Iran-backed Huthi rebel's wound up peace talks in Switzerland without a breakthrough.
On the ground ceasefire violations are continuing even as UN humanitarian agencies warn that civilians are under fire and living in desperate conditions.
"The talks revealed deep divisions between the two sides on the path to peace and the shape of a future agreement... trust between the parties remain weak," UN envoy Ismail Ould Cheikh Ahmed warned.
Ahmed called for a stronger ceasefire agreement and urged UN member states to support his efforts to mediate a dialogue in the run-up to renewed talks next month.
"I have to admit that there were several days when I feared that the two sides would not find a way to make progress on any of the central issues," he said.
"We all know that the path to peace in Yemen will be a long and difficult one -- but we also know that failure is not an option," he insisted.
In Yemen, Shiite Huthi rebels have allied themselves with former president Ali Abdullah Saleh to take on government forces loyal to President Abedrabbo Mansour Hadi.
Iran has supplied weapons to the Huthi, and Saudi Arabia -- with logistical support from the United States -- is leading a Sunni coalition campaign in support of Hadi.
Human rights watchdogs have accused the Saudi-led coalition of the careless aerial bombing of civilian targets and Huthi forces of indiscriminate shelling.
The situation for the surviving civilian population is dire.
The UN High Commissioner for Human Rights, Zeid Ra'ad Al Hussein told the UN Security Council that the Saudi-led coalition was responsible for a "disproportionate amount" of the strikes hitting civilian homes, schools and hospitals.
"Conditions of life have become untenable for the vast majority of people in Yemen," he said.
"I call on the council to do everything within its power to help restrain the use of force by all parties and to urge all sides to abide by the basic principles of international humanitarian law."
The US ambassador to the United Nations, Samantha Power, supported the call for international law to be respected -- but pointed the finger at Huthi forces.
"Militia loyal to the Huthis and former president Ali Abdullah Saleh must stop any indiscriminate shelling of civilian areas, including Taiz, and they must stop their cross border attacks," she said.
"We continue to urge the Saudi-led coalition to ensure lawful and discriminate targeting and to thoroughly investigate all credible allegations of civilian casualties and make adjustments as needed to avoid such incidents."
According to UN figures, the war in Yemen has killed 2,700 civilians, including 637 children, and left four fifths of the 21 million-strong population in need of humanitarian aid.