A cease-fire in Yemen that took effect Monday is generally holding despite what a United Nations spokesman calls "pockets of violence."
Iranian-backed Houthi rebels and a Saudi-led Arab coalition trying to drive them out agreed on a truce ahead of another round of U.N.-sponsored peace talks set for April 18 in Kuwait.
Much of Monday's fighting was reported in the city of Taiz, with one report saying one person was killed and five wounded.
U.N. special envoy for Yemen, Ismail Ould Cheikh Ahmed, is urging all sides to work to make sure the truce holds.
"Now is the time to step back from the brink," he said Monday.
The truce began overnight with the Yemeni government, the Saudi-led coalition that backs it and the Houthi rebels who seized control of Yemen's capital in late 2014 all pledging to abide by the deal. It comes ahead of peace talks scheduled for April 18 in Kuwait.
Ahmed said there is a real chance for rebuilding in a country that has suffered violence for too long.
"I ask all the parties and the international community to remain steadfast in support for this cessation of hostilities to be a first step in Yemen's return to peace," the envoy said in a statement. "This is critical, urgent and much needed. Yemen cannot afford the loss of more lives."
U.S. Secretary of State John Kerry expressed his support Monday morning, tweeting "I welcome start of ceasefire in Yemen." He urged all parties to seize the opportunity to allow humanitarian access and move forward on a political solution.
Like the halt in fighting in Syria, the truce in Yemen also includes pledges for humanitarian access.
A collection of 15 aid groups, including Oxfam, Save the Children and the Danish Refugee Council, called on the international community to fully fund aid and warned of "catastrophic" consequences for Yemenis if the cease-fire breaks down.
"This is a moment of truth for Yemen's civilians," said Norwegian Refugee Council Secretary General Jan Egeland. "A real cease-fire could be the first step towards ending this staggering yet forgotten crisis."
The groups said 2.75 million people have been displaced since the conflict began, and that more than 82 percent of people in Yemen are now reliant on humanitarian aid.
The Saudi-led coalition began airstrikes in March 2015 in defense of President Abdu Rabu Mansour Hadi, who fled to Saudi Arabia after the Houthis marched south from Sana'a to the port city of Aden. The airstrikes and ground fighting in Yemen have killed about 6,000 people.
Two U.N. officials called special attention to the situation faced by children in Yemen, saying kids make up one-third of the dead and are playing a more active role in combat.
Leila Zerrougui, Secretary-General Ban Ki-moon's special representative for children and armed conflict, and Dr. Peter Salama, UNICEF's regional director for the Middle East and North Africa, also said attacks on schools and health clinics have become common.
"Taken together, these data represent a disturbing pattern of flagrant disregard for international humanitarian law and the rights of children in Yemen," they said in a joint statement. "These patterns have far-reaching implications for the stability of Yemen and the future of its children."
Both the Saudi-led coalition and the Iran-backed Houthi rebels said they will adhere to the truce, but respond if attacked.
Fighting was reported in several areas as the hour for the cease-fire approached. One report said at least 20 people were killed.
Several other cease-fires in Yemen have failed and desperate civilians say they hope this one will last.
VOA's Kenneth Schwartz contributed to this report.