Aviation experts looking at images of wreckage from the Azerbaijan Airlines jet that crashed Wednesday in Kazakhstan say small visible holes on the tail end of the plane may be from shrapnel caused by a missile.Russia is coming under increasing pressure to explain whether it may have mistakenly targeted the passenger aircraft in an area that has been increasingly under fire from drones in the war with Ukraine.On Thursday, multiple outlets cited anonymous U.S. officials who said a Russian anti-aircraft system may have brought the plane down.Scripps News has not yet independently verified the reporting.A Kremlin spokesman says it is too early to speculate on the cause of the crash.The flight left Baku, Azerbaijan, bound for Grozny, Russia.Cellphone video captured the Embraer 190 flying in an unstable pattern before dropping into a steep descent and crash-landing just outside an airport in Aktau, Kazakhstan.Of the 62 passengers and five crew on board, at least 38 died.RELATED STORY | Despite recent scares, air travel crashes down worldwide, data showsDozens of survivors were seen emerging dazed from the back section of the plane that flipped upside-down during impact.It's a key part of the plane that holds the crucial black box that may point to what led to the flight's demise.Investigators from several countries are now on the case.Russia initially said a flock of birds may have brought down the plane, an unlikely theory according to aviation analyst Mary Schiavo."The altitude makes me wonder, would the birds have been at that altitude?" Schiavo said in an interview with CNN.Azerbaijan's president said bad weather caused the flight to change course as it headed toward Grozny in the Chechnya part of Russia.The region has been the focus of attacks by drones launched by Ukraine as it fights back against Russia's invasion.Many commercial airlines, including all U.S. carriers, stay clear of airspace in Russia and Ukraine to avoid any risk of flying over an active war zone.