Polish prosecutors have opened a criminal investigation into a plane crash that killed 11 parachuting instructors and students, including the pilot.

The Piper Navajo plane was carrying 12 people when it crashed and burst into flames Saturday just minutes after taking off from Rudniki Airport in southern Poland. One person was also injured. Victim identities are pending DNA testing.

Tomasz Ozimek, a spokesman for the prosecutor in Czestochowa, said the criminal investigation aims to determine whether foul play was involved in the crash.

Ozimek said investigators were also looking at possible plane malfunction, human error or irregularities in the organization of the training flight.