At least eight people, including a child, drowned when an inflatable boat carrying refugees and migrants sank off Greece’s Lesbos island, the Greek coastguard said on Monday.

The coast guard said a Greek navy vessel located the bodies, believed to be of migrants attempting to enter Greece from Turkey clandestinely, on Monday.

“So far the bodies of a man, four women, and a boy have been recovered,” AFP cited a coastguard spokeswoman as saying.

A pregnant woman was also found in the same area and was taken to hospital, the coastguard said.

Greek authorities had received no distress call prior to finding the bodies, the coastguard spokeswoman said.

It was not immediately clear how many others might be missing. A search-and-rescue operation was launched, involving the Greek coast guard and navy, Frontex and a private vessel.

The United Nation refugee agency UNHCR said the number of dead was at least 12. Citing survivors, it said 25 people were on board.

Lesbos was the main gateway into the European Union in 2015 for nearly a million Syrians, Iraqis and Afghans who crossed from Turkey, hoping to head to the more prosperous central and northern European countries. But a European Union-Turkey deal reached last year — in which those arriving on Greek islands face deportation back to Turkey — has significantly reduced the number of people attempting to cross.

Most undertake the short but dangerous journey on overloaded inflatable dinghies or occasionally sailboats. It was unclear what type of vessel was used Monday.

Just over 4,800 refugees and migrants have crossed to Greece from Turkey this year, according to UNHCR data, and about 20 arrive on Greek islands each day. At least 173,000 people, mostly Syrians, landed in Greece in 2016.

Greece is still hosting thousands of refugees and migrants who arrived before the EU-Turkey deal.