Snow and strong winds closed Turkey's Dardanelles Straits to tanker traffic heading south into the Aegean on Thursday, the state Anatolian news agency quoted maritime officials as saying. But traffic heading north into the Marmara Sea was still moving and the Bosphorus Straits further north, which bisect Istanbul, remained open, officials said. It was not immediately clear how many vessels were affected.

The Bosphorus and Dardanelles are the only outlet to the world's oceans for Black Sea states such as Russia exporting oil, grain and other commodities.

Environmental regulations introduced two years ago limit vessels longer than 200 metres and carrying dangerous cargo to transit the straits during daylight hours only.

Copyright Reuters, 2005