WASHINGTON: U.S. authorities are investigating what appeared to be one of the largest human smuggling attempts off U.S. shores in years, after a boat packed with 356 Haitian migrants ran aground in the Florida Keys on Sunday.

Among the passengers, 158 jumped from the boat and attempted to swim toward the shore in Key Largo despite rough seas. They were rescued from the water and detained by the U.S. Border Patrol, according to U.S. Customs and Border Protection (CBP). The other 198 remained on the boat and were taken into custody by the U.S. Coast Guard.

Several migrants were hospitalized for minor injuries but released promptly, a CBP spokesperson said.

No fatalities were reported, unlike an incident in January, when a migrant boat capsized near the Bahamas in rough seas, leaving only one known survivor, one person dead and 38 people missing.

Just days after that, the U.S. Coast Guard intercepted 191 Haitian migrants aboard an overloaded sailing vessel that was believed to be headed for Florida. 

Boat crossings of Haitian migrants have grown more frequent as the Caribbean island nation faces worsening economic and political crises, as well as gang-related kidnappings.

The Coast Guard said it has rescued 1,152 Haitians since October, in addition to 3,900 picked up at sea over the five previous years.

Photos tweeted on Sunday by Chief Patrol Agent Walter Slosar of Border Patrol's Miami Sector show a boat tilting dangerously to one side in the water with passengers dangling off the edge and a group of migrants ashore wrapped in towels.

The migrants in Border Patrol custody will be placed in deportation proceedings, while those in Coast Guard custody will be repatriated to Haiti, CBP said.

In August 2021, the administration of President Joe Biden granted deportation relief and access to work permits to an estimated 155,000 Haitians already in the United States.

But the administration has rapidly expelled asylum-seeking Haitians under rules meant to curb the spread of COVID-19. Thousands were expelled after crossing the U.S.-Mexico border in September and setting up camp under a bridge in Del Rio, Texas.