Knife-wielding principal kills 7 Burmese pupils, wounds 5 othersRAN(i(X)N The principal of a primary school in northern Burma stabbed seven of his students to death and seriously wounded five others today before militiamen shot and killed him Sources here said the unnamed principal called 17 pupils into a room on the pretext of showing them magic tricks He then attacked them Five escaped unhurt, including the man's son who alerted pol ice