(VOVworld) - A cargo ship thought to be carrying hundreds of migrants near Greece sent out a distress call Tuesday. A passenger on board the Moldovan-flagged Blue Sky M called emergency services in Greece earlier in the day as the ship neared the coast of the island of Corfu in the Ionian Sea. Greek authorities scrambled a navy frigate and a helicopter to check on the status of the ship and the nature of the emergency.

Greek coastguard officers set off from Corfu harbour in response to a distress signal from a ship in the area. Photograph: Maria Tzora/EPA

On Sunday, the Greek passenger ferry Norman Atlantic caught fire in the same area, leading to a massive two-day rescue operation by the Italian and Greek coast guards. At least 11 people died in that incident, while more than 400 were rescued.  Authorities are still searching for possible missing passengers from the ferry.