Russia's Rosneft hit by cyber attack

Russia's top oil producer Rosneft says its servers have been hit been a large-scale cyber attack, but its oil production was unaffected.

"The company's servers underwent a powerful hacking attack," the company said on Twitter.

"The hacking attack could lead to serious consequences, but the company has moved to a reserve production processing system and neither oil output nor refining have been stopped."

Rosneft's website was unavailable in Moscow as of 1250 GMT.