MOSCOW, May 2 (Reuters) - Fire broke out at a primary oil refining unit of the Ryazan refinery operated by Russia's Rosneft on May 1, according to industry sources.

Rosneft did not respond to a request for comment.

The governor of Russia's Ryazan region Pavel Malkov said on Telegram early on Wednesday that the region had been attacked by a drone. He did not mention the refinery. (Reporting by Reuters; Editing by Jan Harvey)