A migrant boat carrying more than four times its maximum capacity has sunk in the Black Sea just off Istanbul, killing at least 21 people.
At least 21 people, including children, have drowned and a dozen are missing after an overloaded boat taking migrants towards EU waters sank in the Black Sea just off Istanbul, Turkish officials said.
Those on board were mainly Afghans in search of a better life in the EU. They had reportedly paid several thousand euros each to people smugglers for a seat on the vessel.
The boat was described as a small cruiser that was carrying about 40 people - more than four times its maximum capacity - including 12 children.
Six people were rescued from the stricken boat and 21 corpses recovered, the coastguard said in a statement on Monday, lowering an earlier toll of 24.
It added that search operations were continuing for the dozen still missing.
The boat sank three nautical miles north of the northern entrance to the Bosphorus, one of the busiest shipping thoroughfares in the world.
They had set off earlier from Bakirkoy, an Istanbul suburb on the Sea of Marmara side of the Bosphorus. Turkish media said at least one of those who died could have been a crew member or a smuggler guiding them.
Some reports said Syrians and Turkmen could also have been on board as well as Afghans. Television pictures showed survivors draped in blankets and sobbing as rescue workers offered them soup.
The official Anatolia news agency said rescuers, alerted by fishermen, found the vessel semi-submerged .
It was not immediately clear what had caused the boat to sink, with media citing overloading, bad weather conditions or even a collision with another vessel in the busy shipping lane as possibilities.