VALLETTA, Malta (AP) — A 25-foot boat loaded with migrants capsized off Malta on Friday as rescue operations were under way, killing five people and injuring eight, Maltese officials said.

Twenty-one other survivors were taken to a migrant detention center on the Mediterranean island nation. Search operations were continuing offshore to ensure no other passengers remained in the sea.

Col. Edric Zahra, deputy commander of the Armed Forces of Malta, said the operations center received a call at 10:45 a.m. Friday about a migrant boat around 5 miles (8 kilometers) out and heading toward Malta.

An armed forces aircraft spotted the boat, and a vessel was dispatched to the area. When the rescue operation began, the boat capsized. Zahra said there had been no collision, but that the boat capsized “due to instability” as the passengers moved around.

Migrant rescues occasionally go awry when panicked passengers move to one side of their already unstable vessels eager to get off quickly.

The armed forces sent more boats to try to help, and a police investigation was launched.

The migrants hailed from Egypt, Syria, Ghana and Eritrea. The five killed included four men and one woman.