Orthodox and Catholic Christian children will take part in a day of prayer for peace in Syria on June 1.

Hundreds of children across war-torn Syria, which has suffered immeasurable damage over the past five years, will hold prayer meetings and process to mark International Children's Day, according to Catholic charity Aid to the Church in Need (ACN).

"The children in our home country of Syria are the little brothers and sisters of the suffering Child Jesus," Syrian Catholic and Orthodox Patriarchs said in a joint statement.

"For more than five years now they have been dragged through a cruel war, wounded, traumatised or even killed. Many have lost their parents and everything that was dear to them. Innumerable children were born during the war and have never experienced peace.

"Their tears and their sufferings cry out to Heaven."

They added: "We implore Him, who alone can bring peace: 'Protect and save the children of this land! Hear our prayers, now! Delay no longer in granting peace to our land!'

"'Look upon the tears of the children; dry the tears of the mothers; let the cries of grief at last fall silent!'"

Maronite Bishop Antoine Chbeir of Lattakia told ACN that he hopes the initiative will encourage people around the world to pray for Syria, which in March entered its sixth year of civil conflict.

"We are hoping that this campaign will continue, so that the light of peace can shine forth brightly," he said.

Since the outbreak of civil war in 2011, an estimated 11 million Syrians, half its total population, have fled their homes. Around 4.8 million have taken refuge in neighbouring countries such as Lebanon and Jordan or even further afield. The rest have been displaced internally.

At least 13.5 million people are in need of humanitarian assistance within Syria itself, and 320,000 people have been killed since the conflict began, including nearly 12,000 children.