ATHENS, Greece (AP) — A smuggling boat sank off the southern Greek island of Crete on Monday, leaving three dead, while a large rescue operation managed to save 56 others from the sea, authorities said.

The Greek coast guard said efforts continued deep into the evening to locate other people who might be in the water. It said it was unclear whether anybody was still missing, as the survivors were not in a position to give accurate numbers of how many had been on board when the vessel went down.

The dead were listed as two children and a woman.

Initially, a person claiming to be a passenger who notified authorities by phone said 16 people were on the vessel that sank 12 miles (19 kilometers) east of Crete amid high winds Monday, the coast guard said.

A Greek naval frigate and an air force helicopter took part in the search, together with two coast guard boats and three merchant ships.

There was no indication where the vessel sailed from, how big it was or where it had been heading to.

Greece's Aegean Sea islands are often the destination for thousands of asylum-seekers and migrants from the Mideast, Africa and Asia who cross from the nearby Turkish coast in hopes of finding a better life in the European Union.

But on some occasions, smuggling gangs route yachts south of Crete to head for Italy.