Azerbaijan's transportation minister suggested on Friday that an Azerbaijan Airlines jet that crashed Wednesday in Kazakhstan may have been struck by a weapon.

The minister also said an oxygen tank aboard the plane exploded before the crash.

On Friday, White House national security spokesman John Kirby told reporters the U.S. was investigating the incident and considering the possibility that a Russian weapon system struck the plane.

Kirby said the U.S. had "seen some early indications that would certainly point to the possibility that this jet was brought down by Russian air defense systems," but did not provide further details.

RELATED STORY | Despite recent scares, air travel crashes down worldwide, data shows

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.

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.