Some 5.5 million children, twice as many as in March 2013, have been affected by the war in Syria, the U.N. children's agency Unicef said Tuesday.

The violence has forced approximately 2.8 million youngsters to leave school, a situation that, if it becomes permanent, will have a grave impact on the country's future and its possibilities of reconstruction, Unicef's deputy representative in Syria, Hamida Lasseko, said.

More than 20 percent of Syria's schools are closed and around a fifth of the country's teachers have quit, according to the Unicef report, "Under Siege - The devastating impact on children of three years of conflict in Syria."

The figure might be much higher if Unicef hadn't succeeded in getting some kind of teaching for about 1.4 million children, which includes the lessons offered inside refugee camps.

A total of 1.2 million refugee children live in such camps, chiefly in Lebanon, Jordan, Turkey and Iraq.

The degree of violence and devastation the Syrian population is going through is so high that Unicef estimates that, of the children affected, 2 million need medical treatment or psychological monitoring.

Entering its fourth year, the war in Syria has left more than 140,000 dead and displaced some 9 million people, including 2.5 million who have fled to neighboring countries. EFE