The Central Intelligence Agency infiltrated black groups, the Resurrection City encampment here and the D.C. public school system in the late 1960s despite its own internal findings that "black militant" groups at the time posed no physical threat to the agency.

Documents released by the CIA under the Freedom of Information Act to the Center for National Security indicate that in March 1969 the agency had an informer planted within the D.C. public school system militancy among blacks in the city schools.

The informer, who is not identified in the CIA documents except as "a teacher and head of department" told his CIA contacts that many high school students were carrying firearms "and will probably use these weapons at the slightest provocation."

In addition, CIA informers also reported from the Resurrection City encampment here in 1968 and took photos of a speaker at a Malcolm X Day rally in the District during the same period. The intelligence agency also maintained an almost minute-by-minute log of street activity in the riot areas during the 1968 disturbances following the death of Martin Luther King Jr., according to newly disclosed CIA documents.

CIA officials told both the Rockefeler Commission and the Senate Intelligence Committee investigating CIA abuses that they undertook certain domestic surveillance activities under the code headings of Project Merrimack and Project Resistance to protect the intellence agency's property and personnel.

The Rockefeller Commission noted in its report in 1975 that "the agency's infiltration of dissident groups in the Washington area went far beyond steps necessary to protect the agency's own facilities, personnel and operations and therefore exceeded the CIA's statutory authority."

In its report a year later the Senate committee said surveillance "illustrated fundamental weaknesses and contradictions in the statutory definition of CIA authority."

Neither report indicated the extent of the CIA's surveillance of black groups or the disavowal of any threat they posed.

Protective surveillacne by the CIA was allowed under federal law at the time and is still allowed under the presidential order regulating the U.S. intelligence community signed by President Carter. Legislation proposed by the Senate Intelligence Committee would limit protective surveillance in the future to the immediate vicinity of CIA facilities.

Among the documents released by the CIA was one analysis prepared by the intelligence for the head of its special activities division, which was overseeing the Merrimack and Resistance projects.

The document, which was prepared in January 1969, cities source material gathered from local, state and federal governmental agencies as well as news reports to conclude that they "do not indicate that CIA and/or its personnel and installations are considered at this time to be a primary or sole target by any of the numerous black militant organization or by individual black activists."

Another 1967 CIA memorandum whose contents were made available to The Washington Post notes that growing hostility toward the CIA by some black power groups at the time posed "a new threat to its operations abroad and its image in the United States."

The memo does not mention any threat to CIA property or personnel by-the groups,but notes that the agency had compiled lists of black militants and organizations "which must be of our official concern."

Nevertheless, the CIA cited potential threats t its property and employes as the reason for broad surceillance and infiltration in the late 1960s of black groups

The Scope of the CIA's domestic surveillance was spelled out in a 1968 memorandum on Project Resistance prepared for "headquarters" by a senior agent in one of the intelligence agenc's West Coast domestic offices.

"While the original intent of the project, which was to gather information in support of our recruiters, seems to have develped into a desire to gather as much information as possible pertaining to racial, student and subversive organizations," the agent wrote, "obviously we are only scratching the surface generally in this efort at the present time."

Officials of the District school system said yesterday they were not aware of any CIA into the local school system.

"I wouldn't be surprised at this point to hear they had informants anywhere," said Cassell. "I'm honored to be in the company of many people I respect and admire who are in their files."