MIAMI: More than 100 Haitian migrants have been found on an uninhabited island near Puerto Rico, U.S. Customs and Border Protection said on Tuesday, as a gang blockade of a fuel terminal has caused a humanitarian crisis in Haiti.

The group of migrants includes 63 females, three of whom are pregnant, and 41 males, who were found on Mona Isla by park rangers working for the Puerto Rico Department of Environment and Natural Resources, U.S. Customs and Border Protection spokesman Jeffrey Quinones said on Tuesday.

"What we know preliminarily is that they were transported in just one vessel," Quinones said in a telephone interview.

Smugglers frequently use Mona Island as a drop-off point for vessels leaving the Dominican Republic, and often tell migrants that they've reached Puerto Rico even though Mona island is uninhabited and inhospitable, he said.

Haiti has requested international military assistance to confront gangs that are blocking the Varreux fuel terminal, triggering shortages of food, fuel and diesel.

U.N. Secretary-General Antonio Guterres earlier this month suggested sending in a "rapid-action force," according to a letter seen by Reuters, without describing where the troops would come from.

A proposal presented by the United States and Mexico in the U.N. Security Council on Monday called for a force that would be led by a "partner nation," without identifying the country.