Several people have been injured by a car veering off a road, hitting a seven-year-old boy on a trampoline and flying into a barn roof on its side.

The car first collided with a parked vehicle, broke through a hedge and drove into a garden where it hit the boy on Sunday in the town of Bohmte, in northwestern Germany.

The car then went over uneven ground and it was apparently catapulted into the air and ended up crashing into the roof of a neighbouring barn about 3m off the ground.

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The boy was seriously injured, German Police said.

The 42-year-old driver only suffered minor injuries, but his wife was seriously injured.

Their two sons, aged 11 and 12, and a 13-year-old passenger were also in the car and suffered only minor injuries.

Dozens of firefighters, as well as a dozen ambulances and two rescue helicopters were among the emergency services deployed in response.

Images from the scene showed rescuers cutting through the roof, and wreckage of a playground that the car ran through.

The car had to be removed from the roof with a crane and was carted away by police.

An investigation is underway.