CAIRO (AP) — At least 97 African migrants are missing and believed drowned after their Europe-bound boat sank in the Mediterranean Sea on Thursday, the Libyan coast guard said.

Spokesman Ayoub Gassim said 23 migrants were rescued around 6 miles (10 kilometers) off the Libyan coast after authorities received a distress call. Fifteen women and five children are among those still missing.

He said the boat, which was packed with African nationals seeking a better life in Europe, "completely collapsed."

Chaotic Libya has become a major avenue of migration, with thousands braving the dangerous sea crossing to Europe. More than 4,500 migrants perished on the crossing in 2016 alone.

Smugglers use often rickety vessels to ferry thousands of migrants from the north African country to Europe each month. Mass drownings are common when the overloaded boats capsize or sink.

The German government on Thursday said it would support a ban on the export of boats from the European Union to Libya as part of measures to stem the flow of migrants across the Mediterranean.