Children in the Yemeni capital Sanaa and other districts are cut off from vital help and risk being injured or killed in intense street battles and airstrikes, British charity Save the Children said on Monday.
Escalating violence between Houthi rebels and forces loyal to the late former President Ali Abdullah Saleh over the past few days, combined with new airstrikes from the Saudi-led Coalition, have prevented Yemenis from accessing basic supplies like food, medicine and water and trapped aid workers indoors.
Save the Children called for an urgent ceasefire to allow aid agencies to help children in need of food and medical supplies.
"My daughter is nearly two, and now she recognises the sound of the bombs. I have to explain to her that we can't go outside and why she can't have any sweets", Mohammed Awadh, Communications Manager for Save the Children, said.
Awadh has been sheltering in a small storeroom with his wife and baby daughter since the fighting intensified.
"She cries when we have to go into the shelter – the building has been shaking under the bombardment and it's very dark, we only have electricity for six hours a day."
Families say that children are terrified amid some of the most intense fighting seen in the capital since the war began.
Many Yemeni families haven't had reliable electricity for nearly three years, so they're relying on intermittent solar power.
"The last few days have been unimaginably terrifying for children trapped under intense bombardment. We're not able to get out in Sana'a to reach people with life-saving support while the fighting is this intense," Tamer Kirolos, Yemen Country Director at Save the Children, said.
Children are also at risk of blast injuries from the heavy use of explosive weapons in populated areas, as well as stray bullets and shrapnel.
Ambulances cannot reach the injured and have been shot at, while schools are closed and pregnant women cannot leave their homes to access hospitals. The streets have been deserted amid ongoing clashes and airstrikes.
"Millions of children are already acutely malnourished and sick because of the war and blockade in Yemen, and their families can't go out to get them food and medical care", Kirolos said.
"People are running out of clean water and basic supplies. It was hard to imagine that the situation in Yemen could get worse, but with this latest escalation it has."
The latest violence comes amid a devastating blockade on commercial and aid imports in November by the Saudi-led coalition, which has only partially been lifted.
Save the Children has warned about the prospect of famine and an alarming spike in children with severe acute malnutrition.
"All those fighting in Yemen and their allies must act now to stop the senseless suffering of children because of this conflict, and immediately enact a ceasefire", Kirolos said.
"If this is not a wake-up call to the international community that the war in Yemen must be brought to an end, I don't know what is."