By Osman Orsal
ISTANBUL (Reuters) - Fisherman and coastguards pulled bodies from the sea at the mouth of Istanbul's Bosphorus strait on Monday after a boat believed to be carrying dozens of illegal migrants sank, Turkish authorities and a shipping agent said.
The Istanbul governor's office said four people had been found dead and five rescued alive. Turkish media reported that at least 10 dead bodies were retrieved and around 30 people were missing. Most of those who died were children, the Hurriyet news website reported rescuers as saying.
"They had life jackets. But there were bodies everywhere. Babies, children... We pulled out 15-20 bodies," it quoted fisherman Kadir Sert as saying.
The governor's office said the coastguard had been alerted after the boat sank around 3 miles (5 km) from the coast in the Black Sea at the northern end of the Bosphorus.
One coastguard ship and seven boats were sent to the area along with a helicopter and a diving team, the governor's office said in a written statement. It did not say how many people were on the boat and coastguard officials were not available for comment.
Shipping agents GAC said in a statement the boat had been heading for the Romanian port of Constanta when it sank around 5 am (0300 GMT) and was believed to be carrying around 50 refugees.
Many illegal migrants from Africa and the Middle East pass through Turkey to get into the European Union, often travelling in unsafe boats.
The Bosphorus strait is one of the world's busiest waterways, a vital route for Russian oil and other commodities as the only outlet to the world's oceans from the Black Sea.
The strait bisects Istanbul, a city of around 15 million people. Poor weather frequently forces its closure in winter.
(Reporting by Seda Sezer; Writing by Daren Butler; Editing by Nick Tattersall and Andrew Heavens)