ROME (AP) _ Three people, including one connected with a neo-fascist terrorist group, were arrested with explosives they apparently planned to use in a jail break, police said Tuesday.

Francesco Tamponi, Luca Onesti and Anna Casu were arrested Saturday in Rome and charged with criminal association and possession and transport of explosives, police told a news conference.

''A breakout of notable importance has been avoided,'' said Col. Italo Leopizzi. ''These arrests are the result of four months of anti-terrorist surveillance.''

Police arrested Tamponi, 24, and Casu, 27, as they were on their way to Rebibbia prison, on Rome's outskirts, where Tamponi's brother, Giovanni, is serving a life sentence for armed robbery and double homicide.

Police believe the group planned to use the explosives to free criminals with right-wing sympathies from Rebibbia. They found nearly one pound of explosive in powder form, six detonators and 16 feet of slow-burning fuses.

Onesti, 33, was arrested in 1981, during Italy's strict anti-terrorism laws, for suspected links to the right-wing Armed Revolutionary Nucleus terror group. He finally was released without charge in 1985.