REPUBLIKA.CO.ID, NEW YORK -- The UN aid chief on Tuesday accused Yemen's Huthi rebels of blocking and diverting deliveries of aid to the country's third city of Taez where some 200,000 people are living under siege.

Government forces backed by the Saudi-led coalition have been battling since September to push the Shiite rebels out of Taez as part of their campaign to recapture the capital Sanaa farther north.

"Huthi and popular committees are blocking supply routes and continue to obstruct the delivery of urgently needed humanitarian aid and supplies into Taez city," said Stephen O'Brien, the under-secretary-general for humanitarian affairs.

Trucks carrying aid are blocked at checkpoints and "only very limited assistance has been allowed in," he added in a statement.

O'Brien said it was "unacceptable" that some of the aid destined for the city's needy was being diverted away from those people.

Some 200,000 people are in need of drinking water, food, medical treatment and other life-saving assistance in Taez, a "deeply concerned" O'Brien said.

Yemen descended into chaos when the Saudi-led coalition launched an air campaign in March to push back the advance by the Iran-backed Huthi rebels.

More than 5,700 people have been killed in the fighting while 82 percent of the population -- 21 million people -- are in urgent need of aid.

UN envoy Ismail Ould Cheikh Ahmed has been hold talks for weeks with all sides to try to launch peace talks, but no date has been set for the negotiations.

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