North Korea has again sent balloons carrying rubbish across the heavily guarded border into South Korea following a similar incident earlier over the past week, the Yonhap news agency reported on Sunday. Yonhap cited the South Korean Joint Chiefs of Staff (JCS) as saying that about 600 balloons floated across the border and fell in Seoul and the surrounding province from Saturday evening onwards. The balloons carried trash, such as cigarette butts, paper and plastic bags, like the previous balloons, the report said. The JCS advised local residents not to touch the objects but to report them to…