A massive cleanup began Thursday in Oman's small seaside capital, after Cyclone Gonu ripped down trees and bridges and poured mud onto a city often called the Arab world's tidiest.

Gonu was blamed for 28 deaths so far, including three in Iran, but the storm spared the region's oil installations, with analysts saying its effect was minimal.

As Gonu made its way across the Gulf of Oman to the Iranian coast, the cyclone -- a rarity in the Middle East -- was downgraded to a tropical storm, according to the U.S. military's Joint Typhoon Warning Center.

Entire grassy fields disappeared under several feet of water, as angry waves battered the beachfront normally thronged with European tourists. Several people were seen taking photographs of the unusual destruction in this normally hot and dry country.

Muscat's postcard-perfect mountain backdrop added to the havoc. The torrential rains that poured onto the bone-dry peaks flowed into canyons and dry riverbeds that channeled the raging water directly into the city.

Muscat's lush palm and eucalyptus groves were blown over along with telephone and power lines. Even the normally sparkling blue sea resembled a foamy chocolate milk.

"The capital Muscat became a lake," Oman Royal Police spokesman Abdullah al-Harthi told Iran TV.

Residents spoke of a night of horror as turgid floodwaters ripped into their homes, carried off refrigerators and cars, and left their streets gouged by sinkholes and caked in mud.

Nidhal al-Masharafi, 31, spent all night on his rooftop with his wife and six children.