Spain's police say that one police officer was killed and another seriously wounded when an explosive device went off while they were responding to a shooting in the northern city of Oviedo. Authorities say that there's no indication as of yet that the explosion was terror-related. Police were searching for a suspect who fled an apartment building on Tuesday. Officers had found a backpack containing the bomb there after responding to a call to alert them to shots being fired. Police said that the backpack went off while the bomb squad was trying to remove it from the building.