UN Secretary-General Antonio Guterres warned the Security Council on Tuesday "the war in Ukraine is one of the greatest challenges ever to the international order because of its nature, intensity, and consequences."

Guterres said the war was putting even more pressure on the developing world, with more than 1.2 billion people particularly vulnerable to spiking food, energy and fertilizer costs. 

"We are already seeing some countries move from vulnerability into crisis, and signs of serious social unrest," he added.

Touching on the killing of civilians in Bucha near Kyiv, the UN chief said he will never forget the horrifying images and again called for an independent investigation to guarantee accountability.

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UN chief Antonio Guterres urges independent investigation into Bucha killings

(With input from Reuters)