CAIRO/HOUSTON (Reuters) -Yemen’s Houthi rebels on Friday stepped up attacks on vessels transiting the Red Sea, including a hit that sparked a fire on a fuel tanker operated on behalf of trading firm Trafigura. Trafigura said a missile struck the fuel tanker Marlin Luanda as it transited the Red Sea. The tanker was carrying Russian naphtha purchased below the price cap in line with G7 sanctions, a Trafigura spokesperson said. Firefighting equipment on board was being deployed to suppress and control a fire in one cargo tank on the starboard side, the company said in an emailed statement. “We re…