COTABATO CITY – Tension erupted between government forces and unidentified men with sticks and iron rods who threatened to storm the Sero Central Elementary School, one of the voting centers here for the historic Bangsamoro parliamentary elections on Monday. Colonel Jibin Bongcayao, Cotabato City police chief, said the group of men attempted to enter the voting center along Sinsuat Avenue, but was prevented by police and Philippine Marines. Stat…