Puerto Rico ? Islanders set up emergency shelters and airlines canceled flights as newly born Hurricane Earl churned toward the northern Caribbean on Sunday. Cruise lines diverted ships to avoid the storm’s path.

The U.S. National Hurricane Center in Miami said Earl strengthened into a Category 2 storm with maximum sustained winds of 100 mph, and was expected to continue picking up steam as it moved near the northern Leeward islands.

Center forecasters said Earl could strengthen into a major hurricane as soon as today — probably while east of Puerto Rico. Major hurricanes are those Category 3 and higher.

People on several islands stuffed shopping carts with bottled water, canned food, milk, candles and batteries, while some tourists scrambled to board flights home. Others enjoyed the beach while they could.