4,000 THAIS ARRESTED SINCE MILITARY COUP
Thai mil rulers disclose that more than 4,000 people have been arrested since Oct 6 coup on suspicion of being Communist subversives and nearly 2/3 of total are still in custody; junta extends period of detention without trial and without charges from 1 mo to 6 mos; 2 right-wing newspapers publish list of 57 editors, columnists and reporters, among them some of country's most prominent journalists, who reptdly are going to be arrested; newspapers say at least 50% of those named are Communists; junta spokesman says lists are not official and that those appearing on them 'need have no fear'; fate of 3,070 students, many of whom were arrested during Oct clashes before junta took power, still is unknown; officials concede that 200 leftist students have fled to Laos since crackdowns began; new regulations and edicts issued by junta outlined (M)

