Islanders scrambled to put up storm shutters and stock up on supplies as the fourth major hurricane of the season churned closer to the Caribbean, packing sustained winds of 105 mph.

Hurricane warnings were issued for Barbados (search), St. Lucia, St. Vincent and the Grenadines and Grenada. Martinique was place under a hurricane watch, while Trinidad and Tobago (search) were under a tropical storm warning.

Barbados' Prime Minister Owen Arthur convened an emergency session of the Cabinet Monday to plan a strategy against Hurricane Ivan (search).

"Ivan poses a direct and serious threat to Barbados," Arthur said. Government offices closed early. The first day of the new academic year was scheduled for Monday, but children were ordered to remain home as teachers helped convert school buildings into hurricane shelters.

Ivan's winds weakened from 125 mph to 105 mph Monday, but it was still a powerful Category 2 storm. Forecasters said that the hurricane could regain force by the time it reaches land by Tuesday morning.

"It's still a strong hurricane," said Eric Blake, a meteorologist at the U.S. National Hurricane Center in Miami. "Barbados and other islands could see trees blown down, roof damage and it doesn't take much wind to damage crops."

Ivan's outer bands could start affecting Barbados by late Monday, Blake said.

At 5 p.m., the hurricane's center was about 305 miles east-southeast of Barbados. It was expected to hit the island of 280,000 residents by Tuesday morning and was moving toward the west-northwest near 22 mph.

Hammers pounded throughout the capital of Bridgetown on Monday as metal hurricane shutters and wooden planks were used to cover windows and doors. Islanders also rushed to buy supplies like lanterns, kerosene, bottled water, canned food, flashlights and batteries. Long lines formed at gas stations.

The manager of Dacosta Mannings hardware store in Bridgetown reported a heavy influx of shoppers. "People were here before the store opened and when it did they rushed for the hurricane preparedness center," Donna Susan Hinds said.

Hurricane force winds extend outward up to 50 miles from Ivan's center while tropical storm force winds extend outward up to 140 miles.

Ivan became the fourth major hurricane of the season on Sunday afternoon, following Hurricane Frances, which left at least two dead in the Bahamas and carved out a path of destruction that stretched from the Turks and Caicos Islands to the U.S. state of Florida.

Ivan could threaten Florida but it was too early to tell, meteorologists said. It is also forecast to move over St. Lucia, a former British colony of 165,000 residents.

"We have a major deadly storm approaching St. Lucia and we need to be prepared," said Dawn French, director of the island's National Emergency Management Office.

St. Lucia's Prime Minister Dr. Kenny Anthony called an emergency planning meeting and ordered all government offices and businesses closed on Tuesday.

St. Lucians crammed into supermarkets to buy supplies including candles, batteries and bottled water. "I'm taking no chances. This one looks serious," said 27-year-old shopper Cuthbert Lyons, who is St. Lucian but is on vacation from Britain.