CORALVILLE — Police are investigating whether a pair of armed robberies at two Coralville restaurants are part of a larger robbery spree in the area.Coralville police said two men entered the Wendy’s on Commerce Drive around 1:17 a.m. Wednesday and robbed the restaurant. The men, who were dressed in black pants, gray hooded sweatshirts, skeleton ski masks and gloves, pulled a handgun and demanded cash from the business and employees.