Hurricane Emily, one of the most powerful storms ever seen this early in the Atlantic hurricane season, ripped through Mexico's Yucatan Peninsula Monday, but it began to weaken as it moved onshore from the Caribbean Sea.

Early reports indicate the storm passed directly over Cozumel, a low-lying island with a worldwide reputation among diving enthusiasts, but it appeared the much larger Cancun resort region may have escaped the worst damage. Tens of thousands of tourists and residents fled inland or left the Cancun area before the storm hit.

Just before dawn local time, the hurricane's maximum sustained winds had slowed from 215 to 175 kilometers per hour. Forecasters expect Emily to strengthen again within hours, however, after it sweeps through the Yucatan region and moves across the warm waters of the Gulf of Mexico.

On its current path, Hurricane Emily will strike Mexico's east coast along the U.S. border with Texas, sometime on Wednesday.

The hurricane brushed past the island of Jamaica Sunday, killing four people, and two Mexican pilots died when their helicopter went down at sea while heading toward an oil rig.