Zany, fun-loving CIA agents conducted a series of clandestine pranks and practical jokes on American citizens during the 1960s, according to newly declassified documents.

"It was all in good fun," an agency spokesman said. "After a hard day at the office interrogating double agents or testing LSD on human guinea pigs, the boys sometimes needed to let off a little steam."

Thus was born the so-called Joke Ops division, which phoned in fake pizza delivery orders to Black Panther headquarters, rang senators' doorbells by remote control and occasionally brainwashed young loners to assassinate politicians.

"We were constantly trying to dream up the ultimate prank," one agent recalled. "One day we'd toilet-paper Hubert Humphrey's house. The next, we'd test the effect of bullets on a presidential motorcade in Dallas. It was like 'Candid Camera.' "

Another stunt, code-named "Kill RFK," took place in a crowded hotel kitchen in Los Angeles in 1968. "I don't remember how that one turned out," the agent said. "But I'm sure everyone had a good laugh. The Kennedys loved practical jokes, like the ones they pulled on South Vietnamese President Diem and Marilyn Monroe. Those were good times."