A leak has been found in the Druzhba oil pipeline that links Russia and Germany but officials say sabotage is not suspected.
PERN, the operator of the section of the pipeline in Poland where the leak was discovered, said in a statement on October 12 that the oil link has been partially shut.
"The cause of the incident is not known for the moment. Pumping in the affected line was immediately stopped. Line 2 of the pipeline is functioning normally," PERN said, adding that the leak was detected late on October 11.
The German government said oil deliveries were continuing to two key refineries despite the leak.
"Germany's security of supply is currently guaranteed...Deliveries are uninterrupted," the Economy Ministry said in a statement.
The discovery of the leak in the main route carrying oil to Germany comes amid security concerns over Europe's energy supplies after the Nord Stream gas pipelines in the Baltic Sea recently sprung leaks that officials from both the West and Russia say were caused by sabotage.
Europe also faces a severe energy crisis as a result of Moscow's invasion of Ukraine, which has cut supplies to many countries.
Reuters quoted Mateusz Berger, Poland's top official in charge of energy infrastructure, as saying there were no grounds to believe the leak was caused by sabotage.
"Here we can talk about accidental damage," he said.
The Druzhba oil conduit is one of the world's largest pipelines, supplying Russian oil to much of Central Europe including Germany, Poland, Belarus, Hungary, Slovakia, the Czech Republic and Austria.