A huge explosion was caused by a drones crash into a Russian oil refinery.

The Telegraph said the drone was sent by Ukraine, but the Guardian couldn't say if it was Ukrainian or not. Russian workers are watching a clip that shows a small drone flying over the refinery.

The drones crashes moments later. The metal structure starts to emit smoke. There were no injuries, according to the Guardian.

Whodunnit

At this point, anything could be true.

The smaller country has been using drones and specially trained pilots since Russia invaded it. Despite heavy civilian casualties, Ukrainian soldiers have made progress despite Russian tanks getting mired in mud pits. The know-how to fly a drone into enemy territory is possessed by the Ukrainians.

There is no evidence that the drone came from any particular country. It's possible that it was flown into the refinery by a pilot from Russia.

Since Russia isn't forthcoming about matters of security, it's not clear whether the drone is really Ukrainian. We aren't keeping our hopes up for clear answers because it's more likely that a drone passed through Russian airspace undetected.

There are more reasons to stay on the sky.