Police say a homemade, radio-controlled bomb has exploded and injured seven officers in the southern Russian republic of Ingushetia. The policemen had been responding to a smaller blast in the courtyard of a private home early Sunday. None of the residents was hurt. Federal Interior Ministry officials say the Ingush police fell into a well-known trap, when a first explosion is used to draw law enforcement officers to the scene. Ingushetia has seen almost daily attacks targeting police and other officials. The attacks are blamed on criminal gangs, Islamic fighters and opponents of the Kremlin-backed leadership.