Russian tankers have smuggled jet fuel to Syria through EU waters, bolstering military supplies to a war-torn country where Moscow is carrying out air strikes in support of the government, according to sources with knowledge of the matter. At least two Russian-flagged ships made deliveries - which contravene EU sanctions - via Greek Cyprus, an intelligence source with a European Union government told Reuters. There was a sharp increase in shipments in October, said the source who spoke on condition of anonymity due to the sensitivity of the matter. A separate shipping source familiar with the movements of the Russian-flagged vessels said the ships visited Greek Cypriot and Greek ports before delivering fuel to Syria. The Russian defence and transport ministries did not initially respond to requests for comment. The defence ministry later said EU sanctions on fuel supplies to Syria could not be applied to the Russian air group in that country.

A spokeswoman for EU foreign affairs and security policy said the implementation of EU restrictions lay with member states. Greece's foreign ministry referred questions to the shipping ministry, which was not immediately available to comment.

The Greek Cypriot government said its authorities had not approved the docking of any Russian tankers carrying jet fuel bound for Syria. Syria's civil war, which began in 2011, has become a theatre for competing global powers, with Russia and Iran supporting President Bashar al-Assad, and the United States, Gulf Arab and European powers backing rebels who want to depose him. EU Council Regulation 1323/2014, introduced two years ago, bans any supply of jet fuel to Syria from the EU territories, whether or not the fuel originated in the European Union.