Strikes that have nearly frozen everyday life on France's Caribbean islands burst into clashes on Monday as police battled protesters angry at high prices and resentful of a tiny white elite on lands better known for beach-side vacations.

Police detained about 50 people after coming under a barrage of stones as they tried to take down barricades on the island of Guadeloupe, said Nicolas Desforges, the island's top government official.

Strikers were sprayed with tear gas and several, including union leader Alex Lollia, were injured, France's leftist NPA party said in a statement.

The leader of the LKP Collective that organized Guadeloupe's strike warned that deadly escalation is possible.

"If anyone injures a member of the LKP or a striker on Guadeloupe, there will be deaths," Elie Domota said in a television interview on Saturday.

On the sister island of Martinique, 100 miles (160 kilometers) south of Guadeloupe, police said that as many as 10,000 demonstrators marched through the narrow streets of the capital to protest spiraling food prices and denounce the business elite.

Government offices, schools, banks and stores have been shuttered for most of the past 12 days as islanders demand lower prices and higher wages. The stoppage in Guadeloupe began in late January.

Living costs are high on the French islands, which depend heavily on imports and use the euro. The strike also is exposing racial and class tensions on islands where a largely white elite that makes up 1 percent of the population controls most businesses.

France's minister for overseas departments, Yves Jego, warned in that the strike could cause job losses and Prime Minister Francois Fillon told reporters that barricades "are not part of the legal means of expression."

"Gas stations must be as accessible as possible so the people can get around and the people of Guadeloupe must be able to buy basic goods," said Fillon, whose government deployed more than 100 riot police to the region last week.

Thousands of tourists have canceled vacations on the islands, travel agencies said.

Lines of cars snaked outside of gas stations in Martinique as islanders tried to fill their tanks.

Strikers allowed 28 of the island's 85 gas stations to be resupplied, but forced small shop owners, who had opened over the weekend, to re-close and blockaded industrial zones.

Matthew Cowen, a British IT consultant who lives on Martinique, said Fort-de-France was encircled by barricades, and garbage has been piling up along the island's narrow streets.

"I had a colleague who tried to cycle to the office but he was told under no circumstances would he be allowed to pass through," said Cowen, who lives on the outskirts of Fort-de-France. "It seems there is a certain hardening of the movement and there are a lot of people behind it."