International community 'failing Syria'

Human rights groups have criticised world powers for not implementing a series of UN Security Council resolutions on the conflict in Syria.

Human rights groups say the international community has failed victims of Syria's civil war. (AAP)

More than 20 human rights groups have issued a joint plea for the international community to take responsibility for suffering civilians as Syria's civil war approaches its fifth year.

In a report entitled Failing Syria, they criticised world powers for not implementing a series of UN Security Council resolutions on the conflict.

Three resolutions adopted in 2014 urged armed actors in Syria to protect non-combatants and aimed to secure greater access to humanitarian aid for millions of Syrians.

"However, the resolutions, and the hope they provided, have rung hollow for Syrian civilians. They have been ignored or undermined by the parties to the conflict, other UN member states and even by members of the (Security Council) itself," the report said.

Last year was the deadliest yet in the conflict, with at least 76,000 people killed out of a total of more than 210,000 since it began on March 15, 2011 with peaceful pro-democracy demonstrations.

Since then, 11.4 million Syrians have fled their homes and nearly four million have left the country in what the UN has called the worst refugee crisis in 20 years.

According to the report, Syria's humanitarian crisis is worsening at an alarming rate. Nearly 10 million people inside the country do not have enough to eat, and more than 11 million are in urgent need of clean water.

"This is a betrayal of our ideals, because we're not supposed to be watching people suffer and die in 2015," said Jan Egeland, secretary general of the Norwegian Refugee Council, which contributed to the report.

The 21 groups accused government forces of systematically using rape and sexual harassment as tools of war, and rebels of kidnapping women and children to exchange for prisoners.

Both regime and opposition forces indiscriminately target civilian infrastructure, including schools and health facilities, they said.

As many as 2.6 million children are still out of school, putting entire generations at risk, the UN children's agency (UNICEF) said on Thursday.

"For the youngest children, this crisis is all they have ever known. For adolescents entering their formative years, violence and suffering have not only scarred their past, they are shaping their futures," UNICEF executive director Anthony Lake said.