A military plane belonging to Jordan crash-landed in Belgium ahead of an air show it was supposed to participate in on Tuesday.

The two people on board were seriously injured in the accident, the federal prosecutor's office said, adding that it had opened an investigation into the "emergency landing."

"The two passengers were seriously injured and taken to hospital," it said.

Both were Jordanian nationals and their lives were not in danger, according to a source close to the investigation.

The plane went down late on Monday in a meadow near the southern village of Bleid.

The reasons for the accident were not immediately clear.

A witness told the Belgian newspaper L'Avenir that he had heard four planes flying "quite low" while performing aerobatic drills before one of the aircraft suddenly plunged toward the ground.

Photos published by the newspaper showed the red two-seater sporting the emblem of the Royal Jordanian Falcons aerobatic team, with its fuselage broken in two near the nose.

The aircraft was due to participate in an international air show over the weekend.