A sailboat packed with migrants from Haiti reportedly struck a reef and capsized in the Bahamas, killing at least 10 people, authorities said Tuesday. Low-resolution photos taken by the U.S. Coast Guard during a rescue operation showed roughly 100 people on the boat, clinging to every available space on the overturned vessel off Staniel Cay in the Bahamas. The Royal Bahamas Defense Force and U.S. Coast Guard launched a rescue operation late Monday and the search for survivors was ongoing Tuesday. Officials from both agencies said the exact death toll remained unknown. "Right now the main concern in making sure we can rescue these people and get them back to safety," Coast Guard Petty Officer Jon-Paul Rios said. Staniel Cay is about 125 kilometers southeast of Nassau, the Bahamian capital. It is part of the Exuma chain and is surrounded by low-lying reefs. The boat, in addition to being overloaded, likely encountered choppy water, according to Lieutenant Origin Deleveaux, a spokesman for the Royal Bahamas Defense Force.