ATHENS, Greece (AP) — Greece's coast guard launched a new search and rescue operation Thursday following a distress call from a vessel with 50 migrants on board that was in trouble south of the island of Rhodes.

There was no immediate details yet on that.

The coast guard was already involved in another search operation in the eastern Aegean Sea, two days after the partial sinking of a yacht carrying nearly 100 migrants in which a father and a child went missing.

A total of 96 people were rescued during the operation that took place mainly after dark Tuesday night, plucked from the sea by helicopters, patrol boats and nearby merchant ships after the yacht partially sank 21 nautical miles (24 miles) west of the small Greek island of Halki.

Of those rescued, 72 were transported to Rhodes, five to the island of Karpathos and 19 were picked up from a cargo ship by the Turkish coast guard.

The Greek coast guard said Thursday that a relative has reported the father and child weren't among those rescued. No further information was immediately available.

The coast guard also said it had arrested a 41-year-old suspected migrant smuggler, bringing to four the number of people rescued from the wreck who have been arrested.

Thousands of people continue to make their way to the Greek islands from the nearby Turkish coast, paying smugglers to ferry them in often unseaworthy, overcrowded inflatable dinghies or other vessels.