UNITED NATIONS, March 13 (Xinhua) -- The suffering of children in war-torn Syria "hit rock bottom" in 2016 with the highest number of grave violations against them since verification began in 2014, the UN children's Fund (UNICEF) said on Monday.

UNICEF urged all parties to the conflict, those who have influence over them, and anyone who cared about children, to find an immediate political solution to end the conflict.

At least 652 children were killed last year -- an increase of 20 percent compared to 2015, 255 among them were killed in or near a school, according to a press release from UNICEF.

Maiming and recruitment of children also rose sharply as violence across the country saw a drastic escalation of the conflict, said the UN agency.

"The depth of suffering is unprecedented," said Geert Cappelaere, the UNICEF regional director for the Middle East and North Africa. "Millions of children in Syria come under attack on a daily basis, their lives turned upside down."

The UNICEF issued the press release in order to announce the study Hitting Rock Bottom -- How 2016 became the worst year for Syria's children.

"Each and every child is scarred for life with horrific consequences on their health, well-being and future," Cappelaere added.

The UN agency also highlighted that challenges accessing several parts of the country obstructed a full assessment of children's suffering and delivering urgently needed humanitarian assistance.

The most vulnerable among Syria's children are the 2.8 million in hard-to-reach areas, including 280,000 children living under siege, almost completely cut off from humanitarian aid.

"Beyond the bombs, bullets and explosions, children are dying in silence often from diseases that can otherwise be easily prevented. Access to medical care, lifesaving supplies and other basic services remains difficult," said the press release.

UNICEF also warned that coping mechanisms are eroding both within Syria and across its borders -- families are taking extreme measures just to survive, often pushing children into early marriage and child labour.

After six years of war, nearly six million children now depend on humanitarian assistance, a twelve-fold increase from 2012. Millions of children have been displaced, some up to seven times.

According to estimates, over 2.3 million children are now living as refugees in Turkey, Lebanon, Jordan, Egypt and Iraq.

However, there are some "remarkable stories" of children determined to pursue their hopes and aspirations, the UN agency said.

Darsy, a 12-year-old refugee in Turkey, said: "I want to be a surgeon to help the sick and injured people of Syria. I dream of a Syria without a war so we can go home. I dream of a world without any wars."

"We continue to witness the courage of Syria's children," said Cappelaere. "Many have crossed frontlines just to sit for school exams. They insist on learning, including in underground schools. There is so much more we can and should do to turn the tide for Syria's children."