North Korea has added to its recent barrage of weapon testings by launching four more ballistic missiles into the sea on Saturday. The latest rockets come as the United States sent two supersonic bombers streaking over South Korea. There are fears the dueling display of military might underscore rising tensions in the region. South Korea’s Joint Chiefs of Staff said the four short-range missiles were fired from a North Korean western coastal area around noon. They flew about 130 kilometres toward the country’s western sea. Seoul’s military added that two B-1B bombers had been training with fou…