mattress. the the for a * * 11 NORTH KOREANS SAID KILLED SEOUL. IB ~ South Korean troops killed 11 North Korean infiltrators and seized over 30 Communist weapons in clashes along the' Demilitarized Zone and coastal lines during a three-day period through yesterday, the counterespionage command here announced today. The announcement said nine of the North Koreans were killed in the eastern and. central sectors of the Korean DMZ Friday when Communist groups supported by mortar fire hit four South Korean positions. It said the other two were killed yesterday near Sosan the west coast, 50 miles of Seoul and 75 miles south the DMZ. In the engagements, South Korea lost four men including one army major who commanded a security force detachment.