At least 139 people died and 84 were missing after a boat capsized off the coast of Djibouti, the International Organization for Migration said Sunday. Survivors told the agency the vessel went down in the Gulf of Aden near the Bab al-Mandeb strait late Thursday and early Friday.

The agency said the boat was carrying 305 people from the Horn of Africa nation toward Yemen when it sank.

“No one gets into a boat like that unless they believe there is no other safe way,” IOM Director General Amy Pope said in a statement. “We cannot keep treating these deaths as normal,” she said. “Safe and legal pathways save lives. I am asking governments and donors to act before the next boat goes down.”

Djiboutian authorities were carrying out search and recovery operations, the IOM said, and the agency said it was providing emergency assistance to survivors.