In Cuba residents and visitors in Havana had an opportunity recently to see an exhibition of alleged evidence of United States Central Intelligence Agency activity in Cuba, Angola, Vietnam and Chile.

SYNOPSIS: The exhibition came at a time when Cuban interest in the C.I.A. was high. During the Havana World Festival of Youth, which ended last week, mock trials were featured in which the C.I.A. was a prime target.

Soviet Television report the items on display at the exhibition included material evidence of 20 attempts to assassinate Cuban President Fidel Castro. During the time of the exhibition a news conference was held by six United States citizens who are reported to have formed a group to publish a bulletin exposing the activities of the CIA throughout the world.

According to Reuters news agency a great deal of evidence of C.I.A. activity against Cuba has in the past been published both in Cuba itself and the United States. Reuters say that Cuba has announced that one of its security agents who infiltrated the C.I.A. and worked as a double agent for eight years will shortly be publishing his experiences in a book.

During the mock trials investigating "crimes of imperialism" at least two men claiming to be former C.I.A. agents gave evidence of their involvement in clandestine operations. One, Nicolas Sirgado, is alleged to have been a Cuban double agent and says he was congratulated on his C.I.A. work by former U.S. Secretary of State Henry Kissinger.

On Wednesday last week (2 August) Cuba called for further investigation into the assassination of U.S. President John Kennedy, charging that the C.I.A., Cuban counter-revolutionaries and the Mafia had links with his death.