CAIRO (Reuters) - Yemeni Houthi rebels called on the United Nations on Saturday to seek an end to Saudi Arabian air strikes against them that they described as blatant aggression against the country.

Warplanes from a Saudi-led coalition are targeting Iranian-allied Houthis who have seized the capital Sanaa and large areas of the country.

"We want to emphasize the grave and tragic situation that comes in the light of the continued Saudi blatant aggression on our country and our people," said the Ansar Allah Zaydi Houthi movement's foreign relations official Hussein al-Ezzi, in a letter addressed to the U.N. secretary general.

Zaydis are a sect of Shi'ite Islam that predominates in Northern Yemen.

"We look forward to your active humanitarian role...to put an end to the Saudi aggression against our people without any justification or reason," the letter said, listing a number of areas and damage the strikes had caused so far.

The United Nations says the conflict in Yemen has killed 600 people, wounded 2,200 and displaced 100,000 since Houthi rebels allied with Iran seized the capital Sanaa in September.

Saudi Arabia believes the Shi'ite Muslim Houthi group is a proxy for its regional rival Iran. Saudi backing for the resistance in Yemen's mostly Sunni Muslim south has raised fears that Yemen could descend into all-out sectarian war.

(Reporting by Mohamed Ghobari; Editing by Ralph Boulton)