A man held hostage for two hours by a teenager who had just gone on a school shooting spree says the boy told him he had killed for fun and wanted to attack a second school, a magazine reported Wednesday.

Igor Wolf, the hostage, said 17-year-old Tim Kretschmer burst into his car March 11 after fleeing the school where he had perpetrated a bloodbath, put a gun to Wolf's head and forced him to drive away at high speed, Stern weekly reported.

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Wolf said Kretschmer asked him if they could find another school and said he had killed "because it's fun," the magazine reported

Excerpts from the interview, to be published Thursday, were released in advance Wednesday.

Kretschmer killed 15 people before turning his gun on himself.