UN Secretary-General Ban Ki-moon warned world powers on Thursday not to repeat in Syria the mistakes they made in Bosnia, during a landmark visit to Srebrenica where UN peacekeepers failed to prevent the massacre of 8,000 Muslim men and boys.

The United Nations had designated the enclave in eastern Bosnia a "safe haven" for Muslim refugees, but peacekeepers stood by helplessly as Bosnian Serb forces carried out the slaughter in 1995.

It followed three years of hand-wringing and hesitation by divided world powers reluctant to intervene in the 1992-95 Bosnian war. About 100,000 people died before they finally did.

During the conflict in Syria, the U.N. Security Council, split between Western powers on one side and Russia and China on the other, has proved similarly helpless.

"I don't want to see any of my successors after 20 years visiting Syria and apologising for what we could have done now to protect civilians in Syria, which we are not doing," Ban said, after laying flowers at a white marble memorial to the Srebrenica victims.

"Never Srebrenica," he said, "Nowhere, to nobody."

-- Reuters