Poland's highest state officials have reburied the remains of 35 national heroes, men who fought the Germans during World War II only to be killed after the war by a new communist leadership that felt threatened by their patriotism.

The remains of the victims were recently recovered from unmarked mass graves with bullet holes in the back of their skulls.

Prime Minister Ewa Kopacz said at a ceremony Sunday at Warsaw's Powazki cemetery that the nation remains indebted to them, hailing their "heroism of the highest order."

The burial is part of efforts made by democratic Poland since the toppling of communism in 1989 to recognize war heroes and anti-communist activists who were persecuted, killed and deliberately purged from records during the decades of communist rule.