Mirvat Ibrahim fled Syria's Aleppo for Lebanon four months ago. Now she is safe, but struggling to feed her eight children including malnourished nine-month-old Shorouq.
"I want to feed my children, but what can I make them to eat? We have nothing," she says.
Her children are among the estimated 5.5 million people that aid groups say have been affected by the Syrian conflict, which entered its fourth year on Saturday.
Displaced from their homes and deprived of health care, education, and security, a generation of Syrian children risks being "lost forever", a group of aid organisations warned.
Ibrahim, her husband and eight children share a tent in a muddy field at Kab Elias, in the Bekaa valley in the east of Lebanon.
The family relies completely on aid groups which have supplied them with a mattress and a heater. They eat one or two meals a day.
Her eldest child collects leftover vegetables from the local market to supplement what they have. But Shorouq still cries without cease -- she is still suffering from malnutrition.
She should weigh around between 7.5-9 kilos (16.5-19.8 pounds), but instead she weighs 3.8.
She "vomits and has diarrhoea," Ibrahim says. "I breastfeed her but she hasn't grown."
Linda Berbari, country representative for the International Orthodox Christian Charities NGO, said 5.9 percent of Syrian refugee children under the age of five in Lebanon are suffering from "severe malnutrition".
The plight of Syria's children was highlighted on Saturday by two UN agencies and three NGOs, which warned that they were living "a childhood that none should endure".
"The children of Syria cannot, and must not, face another year of this horror -- the violence and cruelty that has scarred their lives for three long years," UNICEF executive director Anthony Lake said.
Antonio Guterres, the United Nations High Commissioner for Refugees, said: "Syrians represent the largest population of forciblydisplaced people in the world."
"They need and deserve to be protected, healed and educated."
- 'Everybody is losing' -
He urged the international community to open their doors to those fleeing, particularly in the West where governments have been reluctant to accept large numbers of refugees.
Desperate families have crossed borders illegally and even attempted perilous sea crossings in a bid to find refuge in Europe.
"To see Syrian children drowning in the Mediterranean today after fleeing the conflict... is something totally unacceptable," Guterres said.
"Borders need to be open everywhere, visa policies need to be open everywhere, family unification programmes need to exist everywhere."
He also called on the international community to renew its efforts to stop the conflict.
"There is no military solution to this war. It is clear that nobody is winning; everybody is losing," he said.
"The war would stop now if arms and money would not be provided to both sides."
The aid groups said 37,000 refugee babies had been born since the conflict in Syria broke out in March 2011.
A total of 1.2 million Syrian children are now living as refugees in host countries, almost half a million in Lebanon alone.
Save the Children head Justin Forsyth described cases of children who had been tortured, starved or targeted in attacks.
"Hundreds of thousands of children are growing up having known nothing but the horrors of this war and the chaos and uncertainty that it has bought to their young lives. It has to stop," he said.
The groups said one-fifth of schools in Syria had been destroyed, damaged or converted to military use, and nearly three million children were not attending classes on a regular basis.
The collapse of the education system poses a "threat to long-term prospects for a more stable and prosperous Syria", they warned.
The conflict, they added, has "devastated the lives of millions of children and young people -- and a generation is at risk of being lost forever".