At least 11 people have died and 31 suspected migrants were rescued Thursday after a vessel capsized near Puerto Rico, a US Coast Guard official said Thursday.

A US Customs and Border Protection aircrew on Thursday morning spotted the troubled vessel and people in the water about 10 nautical miles north of Desecheo Island, Puerto Rico, the Coast Guard said in a news release. The people didn’t appear to be wearing life jackets.

Crews were able to pull 31 survivors from the water, a spokesperson with the US Coast Guard’s 7th District told. Eleven bodies have also been found, he said.

The search and rescue operation is ongoing, the agency said.

US Customs and Border Protection and Puerto Rican police are also on the scene, the spokesperson said.

The nationality of the suspected migrants is unknown.