BANGKOK—Thai authorities scrambled Friday to contain the country’s second oil spill in less than three weeks in the Gulf of Thailand. An estimated 5 tons (1,320 gallons) was believed to have leaked 20 kilometers (12 miles) off the eastern province of Rayong, in the same location where at least 22 tons (5,800 gallons) spilled into the sea on Jan. 25. The cleanup from the earlier spill from a mooring point was declared completed last week, but only after some oil made it on to one of the shoreline beaches. The new leak was reported Thursday, and believed to have come from an underwater pipeline to the mooring point that was undergoing repairs, according to its operator, Star Petroleum Refining Co.. Navy spokesperson Vice Adm. Pokkrong Manathatphalin said three large oil slicks from the leak were detected and chemicals were being applied to disperse them. Star Petroleum said in a statement …