ISTANBUL Heavy fog on Wednesday forced the closure of Turkey's Bosphorus and Dardanelles straits, vital routes for Russian oil and other commodities, to shipping traffic, agent GAC said.
Four tankers were waiting to travel south at the mouth of the narrow Bosphorus strait, which links the Black Sea with the Mediterranean, GAC said.
Traffic at the Dardanelles Strait, at the other end of the Sea of Marmara, was also blocked, with a total of 13 northbound and southbound vessels waiting.
Ferry traffic in Istanbul was also halted.
Reduced visibility due to poor weather in the winter frequently requires maritime officials to shut the Bosphorus, disrupting the flow of Russian oil and grain to world markets.
Each year about 150 million metric tons of crude and petroleum products pass through the waterway, which bisects Istanbul, a city of 15 million people.
(Reporting by Ece Toksabay, Editing by Humeyra Pamuk)