SAN JUAN, Puerto Rico (AP) — The US Coast Guard said Tuesday that it rescued 34 Haitian migrants abandoned by smugglers on an uninhabited island near Puerto Rico, the second such incident in less than a month.

The migrants were found after employees with Puerto Rico’s Department of Natural Resources reported seeing multiple campfires on Monito Island, located in the treacherous waters that separate the US territory from the Dominican Republic.

The rescue occurred Monday during swells of up to 15 feet (five meters) as the migrants took turns jumping into the water where a small Coast Guard boat awaited. The rescue took five hours, officials said.

The 26 men, seven women and one boy were then transferred to US Border Patrol agents in Puerto Rico.

In November, the Coast Guard rescued 12 Haitian migrants who had spent five days on Monito Island. In late June, another 27 Haitian migrants were rescued from the same tiny island.

A growing number of Haitians are fleeing their country amid deepening poverty and political instability, with many crossing the border into the Dominican Republic and then paying smugglers to ferry them to Puerto Rico only to be dropped off halfway. Dozens of migrants have died this year as the rickety boats that transport them capsize in rough waters.

The Coast Guard said that it has detained more than 320 migrants from October 1 to November 30, the vast majority Dominicans. All are transferred to US Border Patrol agents and returned to their home countries unless they request asylum or they have prior criminal records in the US.