Eleven people were killed and one person seriously injured after a plane from a parachute club crashed in southern Poland yesterday, with local media suggesting the light aircraft may have been carrying too many passengers.

"Twelve people were on board the plane and the only survivor was taken to hospital and is in a serious condition,” Justyna Sochacka, a spokeswoman for the emergency services, told AFP.

The light twin-engine aircraft, a Piper Navajo, took off from an airfield in Rudniki near Czestochowa with 11 parachutists and a pilot on board, according to reports.

The causes of the crash was not immediately known, but the Polish media suggested the plane's engine may have failed due to there being too many passengers on board.

Quoting anonymous sources close to the case, the PAP news agency reported that the aircraft could have been overloaded, and temperatures of 27 degrees Celsius (80.6 Fahrenheit) in the area may have contributed to the engine overheating.

Eyewitnesses said its engines began making an odd, droning sound before the aircraft began to fall from the sky.

"It was flying from the south and the engine was making strange sounds," said eyewitness Barbara Minczykiewicz, a resident of the village of Topolow where the plane crashed, quoted by Poland’s Gazeta Wyborcza broadsheet daily.