An Air Force bomber jet crashed during a training mission at a South Dakota base Thursday, officials confirmed.

All four aircrew members on board were safely ejected from the B-1B Lancer before it smashed into the ground just before 6 p.m. at Ellsworth Air Force Base, a spokesperson from the unit said.

The crew had been attempting to land the heavy bomber jet during a training mission when it lost control of the aircraft.

The Air Force could not say whether any injuries were reported.

Multiple local fire departments responded to the accident following reports of a small fire.

The cause of the accident is not yet known, but a popular military forum claims icy and foggy weather conditions could be to blame.

At the time of the crash, the area was facing below-freezing temperatures and cloudy weather.

A board of Air Force officers will investigate the accident.

The crash is the latest in a series of military aircraft training snafus, though previous collisions proved fatal.

Eight crew members were killed in November when their Osprey aircraft crashed off southern Japan and sank into the ocean during a training mission.

Investigators ruled the tragedy was caused by a plane malfunction rather than human error.

In August, there were two separate fatal Marine Corps-related aviation accidents in less than a week — three US Marines died when their plane crashed while training in a joint-nation exercise in Australia just days after a soldier died while piloting a helicopter during training in California.