WASHINGTON (NEXSTAR) – U.S. officials say Russia could be behind a passenger plane crash in Kazakhstan that left at least 38 dead Wednesday, but Russia is denying any involvement.

U.S. officials say it appears the plane was hit by a Russian anti-aircraft missile, but investigators haven’t been able to confirm exactly what happened.

As investigators scoured the crash site in Kazakhstan this week Russian President Vladimir Putin expressed condolences for the victims.

Putin denied any Russian involvement even as U.S. officials say there are early signs a Russian anti-aircraft missile may have struck the plane.

Azerbaijan says it’s launched a criminal investigation.

The idea of a Russian missile hitting the plane comes amid speculation Russia was fending off Ukrainian drone attacks in the area of Russia where the plane was trying to land.

Ukraine launched drones at Russia after Russia attacked Ukraine’s energy grid on Christmas.

Before the crash, the plane went off course for reasons that still aren’t clear.

Russia says any guesses about the cause of the crash would be wrong until officials from Azerbaijan and Kazakhstan finish their investigations.

U.S. officials are not publicly commenting but say if this is Russia it shows the country’s recklessness in its war against Ukraine.