In the first quarter of 1991, 37 people were detained in Great Britain under the Prevention of Terrorism Act 1989. The quarterly average for 1989 and 1990 was 47. Twenty-four of the detentions in the first quarter were in connection with Northern Irish terrorism and 13 were in connection with international terrorism. In regard to Northern Irish terrorism, 16 exclusion orders were made in Great Britain during the most recent 4 quarters against persons not excluded previously. Those persons detained under the Act for international terrorism may be deported, excluded, or removed under the Immigration Act of 1971. Only 5 of the 71 persons detained were excluded since the beginning of 1988, much lower than the 49 who were detained, deported, or removed over the 1984 to 1987 period. For the latest 4 quarters, 27 of the 198 persons detained were charged with an offense. In the first quarter of 1991, three persons were either charged with an offense, deported, removed, or excluded -- eight percent of the total number detained. The average proportion was 21 percent during 1989 and 1990. 12 notes and 7 tables