'We are losing the fight against famine'

International aid agencies are losing the fight against famine in Yemen, where 3.5 million people may soon be added to the eight million Yemenis already facing starvation, the UN aid chief warned Friday.

A sharp drop in the value of Yemen's currency that has sent fuel prices spiraling compounded with renewed fighting has led to a worsening of what the United Nations already considers the world's worst humanitarian crisis.

"We are losing the fight against famine," Mark Lowcock, the under-secretary-general for humanitarian affairs, told the Security Council.

"We are already seeing pockets of famine-like-conditions -- including cases where people are eating leaves because they have no other form of sustenance," he said.

Three quarters of Yemen's population -- or 22 million people -- are in need of humanitarian aid, including eight million who need food relief to survive, according to UN figures.      

Meanwhile, Human Rights Watch said on Friday said Saudi Arabia is trying shut down a UN-backed war crimes investigation in Yemen,  calling it a "blatant attempt to avoid scrutiny" of its conduct in the country.