Russia has cut oil supplies to Poland, Germany and Ukraine amid a trade row with its neighbour Belarus.
The Russian state pipeline operator, Transneft, said it cut supplies on the Druzhba pipeline to prevent Belarus illegally siphoning off oil.
BBC economics correspondent Andrew Walker says the suspension is an uncomfortable reminder to Europe of the large and growing role that Russia has in meeting its energy needs.
After cutting off gas to Ukraine and much of western Europe last year, Russia is flexing her economical might and control over Europe further by cutting the Oil to Poland, Germany and Ukraine. Will we have to pander to the Russian state in the future to make sure our oil run machine continues to function? Exactly how will Russia use this leverage in the coming years as oil and gas starts to run out?