A bomb blew up at a Budapestbranch of the Hungarian CIB Bank in the early hours of Mondaymorning, but police said no one was injured.The device went off shortly after 4 a.m. (0300 GMT), police said. A Reuters camerawoman on the scene saw some damage to the building."Based on preliminary data, the explosion was caused by an explosive device of unknown structure and substance," police said in a statement.CIB Bank is a unit of Italy's Banca Intesa. A CIB spokeswoman declined to comment.