SEOUL, South Korea — Six Americans were detained Friday in South Korea for trying to send 1,600 plastic bottles filled with rice, miniature Bibles, $1 bills and USB sticks toward North Korea by sea, police said. The Americans were apprehended on front-line Gwanghwa Island before throwing the bottles into the sea so they could float toward North Korean shores on the tides, two Gwanghwa police officers said. They said the Americans are being investigated on allegations they violated the law on