In a sign that the bloodbath may feature in the campaign for national elections this year, Edmund Stoiber, conservative challenger to Schroeder, said violent games should be banned.

According to Der Spiegel news magazine, Steinhauser spent much of his time playing violent computer video games. His favourite was called "Counterstrike" in which anti-terror units wearing masks battle each other to death.

A former classmate, Isabell Hartung, told Reuters that Steinhauser was intelligent and well-liked by his peers. But she said he often fought with teachers and had "bad relations with his parents."