Updated

Yemen's Shiite rebels caused "slight damage" to a Saudi oil tanker off Yemen's western coast, Saudi TV reported on Wednesday shortly after the rebels said they targeted a Saudi "battleship."

The coalition announcement, carried by state-run al-Ekhbariya TV channel, said the rebels, known as Houthis, "had almost caused an environmental disaster." Earlier, the rebel-run Al-Masirah TV said their "naval forces have targeted the Saudi Dammam battleship off the western coast." The report didn't elaborate.

The Saudi-led coalition backing Yemen's internationally recognized government of Abed Rabbo Mansour Hadi has been fighting to defeat the Iran-aligned rebels and restore Hadi to power since March 2015.

The coalition has repeatedly accused Saudi rival Iran of arming the rebels, allegations the Houthis and Iran deny.

In recent months, raging battles have been taking place along Yemen's west coast especially around the key port city of Hodeida as well as other rebel-held areas.

On Tuesday, the United Nations Children's Fund criticized an attack on a vital water facility in Yemen's northern Saada province, a Houthi stronghold.

UNICEF regional director Geert Cappelaere said the attack, which took place earlier in the week, is the third to target the same water facility. He said the attacks have left over half the project damaged, "cutting off 10,500 people from safe drinking water."

Cappelaere warned against continued attacks on water systems saying they increase the likelihood of water-borne diseases spreading in the war-torn country.

U.N. special envoy for Yemen Martin Griffiths held meetings with the warring parties in recent weeks amid efforts to restart peace talks after a two-year hiatus.

Yemen's three-year stalemated war has damaged Yemen's infrastructure, crippled the health system and pushed it to the brink of famine.

The impoverished country is also now in the world's worst humanitarian crisis, with more than 22.2 million people in need of assistance. Malnutrition, cholera and other diseases have killed or sickened thousands of civilians over the years.