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

The U.S. National Hurricane Center in Miami said that Earl, with maximum sustained winds of 75 mph, could hit the northern Leeward Islands later Sunday.

Center forecasters said Earl could strengthen into a major hurricane as soon as Monday – 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.

“I’m just trying get a good suntan in while the weather is still cooperating,” said Linda Curren of New York City, sunbathing on San Juan’s Ocean Park beach as a few surfers paddled into pounding waves.

In Antigua, the V.C. Bird International Airport closed, while regional airlines LIAT and Winair suspended flights. Cruise ships diverted to other ports in the Caribbean and Mexico.

In St. Kitts and Nevis, authorities urged islanders to take all necessary precautions for the approaching hurricane, which is dwarfing the tiny island nations and territories of the northern Caribbean.

“We really don’t want any loss of life, whether by persons who are careless or by security or emergency persons trying to rescue people,” said Carl Herbert, head of the local emergency management agency.

Hardware stores were doing a brisk business in plywood and boards as jittery residents and employees of gleaming tourist hotels prepared to safeguard windows and doors.

“We haven’t been hit for quite a few years, but you may never know – this might be the time,” said Ashley Benta, from the Antiguan town of Gray’s Farm.

Fishermen and yacht owners tied down vessels in harbors scattered across the northern Caribbean.

“We’re watching and waiting at this point,” said June Otway, a manager of Puerto Del Rey, a 1,100-slip marina in northeastern Puerto Rico.

Earl could bring battering waves and a storm surge of up to three feet above normal tide levels in some areas, according to forecasters. Heavy rains could cause flash floods and mudslides. Forecasters said Earl had several bands of thunderstorms wrapped around its center.

Late Sunday afternoon, Earl was about 150 miles east of Barbuda. Hurricane-force winds extended outward up to 30 miles from its center.

Warm ocean temperatures of 86 F (30 C) are helping to fuel the storm. Forecasters said there is a chance the hurricane could brush the U.S. Mid-Atlantic region toward the end of the week, with its closest approach to North Carolina on Thursday.

Meanwhile, the Category 1 Hurricane Danielle was bringing dangerous rip currents to the U.S. East Coast. It was gradually weakening as it headed over the open Atlantic northeast of the British territory of Bermuda.