The National Organization for the Reform of Marijuana Laws (NORML) asked the Department of Defense yesterday to discontinue random testing of urine to detect marijuana use among members of the armed forces.

NORML asserted that random surprise tests used since last year are an invasion of privacy. The organization also said the testing of an estimated 1.5 million military personnel a year could result in thousands of men and women being wrongly accused of drug use because of questionable accuracy of the tests.

The Defense Department began using the tests last February as a basis for discipline or discharge of personnel, according to John H. Johns, assistant secretary of defense for drug and alcohol abuse prevention.

In a recent interview with The Washington Post, Johns said some military commanders order surprise "unit sweeps" in which all personnel must submit to urinalyses -- a procedure that Johns does not endorse but which individual commanders are authorized to use.

NORML's 51-page petition is the first step in a possible legal action, according to Kevin Zeese, the group's director.

Johns said all tests that record positive results are double checked, and said that he believes the methods are "reliable to the nth degree."