Madrid - Three Spanish air force pilots were killed Tuesday in an accident involving two Mirage F-1 fighter-bomber planes, Defence Ministry sources said.

The planes, which were on exercise flights, crashed in a private property and a nearby terrain near Albacete in the south-east.

Witnesses said they heard an explosion and saw fire and smoke from several kilometres away. It was not clear whether the planes had collided in the air.

One of the planes had two and the other one pilot. The three bodies were retrieved from the wreckage. The crash did not cause further injuries or damage.

The French-made fighter-bombers had been "modernized" recently, said the ministry, which was investigating the causes of the accident. (dpa)