ATHENS, GREECE -- Forty-two people have been rescued while another three are missing after a boat believed to have been carrying migrants sent out a distress call while sailing in the Mediterranean south of the Greek island of Crete, the Greek coast guard said Thursday.

Officials said they were alerted by the Italian coast guard overnight about a boat in distress 27 nautical miles (31 miles, 50 kilometres) south of Crete. Greece's coast guard said 40 people were rescued by ships that had been sailing in the area, while another two people were later rescued by a Greek navy helicopter.

The coast guard said survivors have told them that there are three others still missing, and that officials are conducting search and rescue operations in the area. It was not immediately clear what kind of vessel the passengers had been on, or why the boat sent out a distress call.

Thursday's rescue occurred days ahead of a trial of nine Egyptian migrants in Greece, accused of causing a deadly shipwreck last year.

Greece lies along one of the most popular routes into the European Union for people fleeing war and poverty in the Middle East, Africa and Asia. While most of those cross into the country’s eastern Aegean Sea islands from the nearby Turkish coast, others try to skirt Greece altogether and head from north Africa to Italy across the longer and more dangerous Mediterranean route.

The overloaded boats frequently run into engine or other trouble and can get blown off course, ending up close to southern or western Greece.

In June 2023, a massively overcrowded fishing trawler that had set sail from Libya sank into deep waters off the western Greek coast, killing an estimated 500 people. Just over 100 people were rescued, while fewer than 80 bodies were recovered.

Nine Egyptian survivors of the shipwreck are due to go on trial next week in the southern Greek city of Kalamata, accused of migrant smuggling, membership of a criminal organization, causing a deadly accident, and other criminal offenses.

Their Greek lawyers on Thursday claimed they had been falsely accused, noting that an official investigation into the cause of the sinking is still ongoing.

“For nearly a year now, nine people have been in prison without knowing what they are in prison for,” lawyer and defense team member Dimitrios Choulis told reporters in Athens.

“They managed to survive without knowing how to swim, without life jackets, having faced certain death." Authorities had gotten nine other survivors to testify against them, Choulis said.

“For me, it is very sad to visit and see people in prison who do not understand why they are there.”

Derek Gatopoulos in Athens contributed