London, May 24 (IANS/RIA Novosti): The UN Security Council is suffering from a failure of leadership and looks "tired, out of step and increasingly unfit for purpose", human rights organisation Amnesty International has said in a report.

Analysing the international community's reaction to popular uprisings in the Arab world, particularly in Syria, the report said the Security Council's failure to take action to stop Syrian President Bashar al-Assad's crackdown on protestors has left the council looking "redundant as a guardian of global peace".

"There is a clear and compelling case for the situation in Syria to be referred to the International Criminal Court for investigation of crimes against humanity," said Amnesty International's secretary general Salil Shetty.

"The determination of some UN Security Council members to shield Syria at any cost leaves accountability for these crimes elusive and is a betrayal of the Syrian people," he said.

Russia and China, two of the UN Security Council's five permanent members, have twice vetoed UN resolutions on Syria over what Moscow called a pro-rebel bias.

According to UN estimates, more than 90,000 people have been killed in Syria since the beginning of the uprising against Assad in March 2011. Syrian authorities say they are fighting terrorist gangs affiliated with the Al Qaeda.

Amnesty also highlighted the global arms trade and called for nations to agree on a global arms trade treaty to be negotiated at an international conference in New York in July.

The group said the Security Council's five permanent members account for some 70 percent of the global arms trade.