The escalation has affected western Taiz, southern Hudaydah, Marib and other areas, forcing families to leave their homes and placing additional pressure on communities already facing a prolonged humanitarian crisis.

At least nine children have been reported killed and 12 injured since September 3, according to UNICEF. Three other children are reported missing following an attack on a road linking Yemen’s western coast with Aden.

The violence has also disrupted basic services. UNICEF said 26 health facilities it supports have experienced interruptions, while 243 schools have either closed or suspended classes, affecting more than 137,000 students.

The UN children’s agency said it is expanding its emergency response to assist up to 231,000 people affected by the latest escalation.

In Taiz, UNICEF has supported health facilities and distributed hygiene supplies and water tanks, while additional water and sanitation assistance has been provided in Marib. Nine mobile health and nutrition teams have also been redeployed to displacement sites and affected communities in Aden, Marib and Taiz.

Emergency water and sanitation operations are expected to reach more than 200,000 people with safe drinking water, hygiene supplies and urgent repairs to damaged infrastructure.

UNICEF said child-protection teams are providing psychosocial support and case management, with particular attention to unaccompanied and separated children. Teams are also working with communities to reduce the risks posed by explosive remnants of war.

"Children in Yemen were already living through one of the world’s most severe humanitarian crises,” said Edouard Beigbeder, UNICEF Regional Director for the Middle East and North Africa. He said many families had been forced to flee with little more than what they could carry, adding that the latest violence was further undermining the limited stability available to children who have already experienced years of conflict, hunger and disrupted education.

The humanitarian impact is also extending beyond Yemen. UNICEF said more than 2,000 people, including children, have reached Djibouti after crossing the Bab el-Mandeb Strait. The journey has exposed those making the crossing to extreme heat, dehydration and protection risks.

UNICEF is working with authorities in Djibouti to provide newly arrived families with clean water, sanitation and hygiene assistance, as well as child-protection services and referrals for children considered particularly vulnerable.

Yemen was already facing significant humanitarian needs before the latest escalation. UNICEF estimates that 12.2 million children require humanitarian assistance, while more than 2.2 million children under five are acutely malnourished. Of those, more than 515,000 are experiencing severe acute malnutrition.

The agency also estimates that 3.2 million school-aged children are out of school and that around 17.8 million people lack adequate access to health care, water and sanitation services. Only about 60 percent of health facilities are fully operational.