A letter bomb mailed to Josef Ackermann, chief executive of Deutsche Bank, was primed to cause burns to his hands and face, German police said Thursday, a day after the device was intercepted before it could detonate. Mail staff at Deutsche Bank became suspicious Wednesday when they noticed an odd A5-sized envelope. An X-ray scanner showed it contained wires and metal parts and the police was called in. The letter was personally addressed to the head of Germany's biggest bank. A Frankfurt police spokesman, Udo Buehler, said it contained an incendiary powder, not an explosive, and would have detonated if it had been opened. He described it as a "very dangerous bomb."