(Gladstone, OR)  --  Police are looking for two suspects in the armed robbery of an Arco station in Gladstone.  Authorities say the suspects, who wore bandannas over their faces, were armed with a semi-automatic handgun when they entered the store on East Arlington around 4:40 a.m. yesterday morning.  Police say the suspect carrying the gun was white with light-brown hair and blue eyes, and a slim build.  The second suspect is reported to be black, between five-nine and five-eleven and weighing 160 pounds.