Police prevented an attempt to break prisoners out of a top-security Brazilian penitentiary on Monday and found two missiles and a machine gun that were to have been used in the attack.

Police investigator Geraldo Takushi said gunmen fired shots against the Presidente Bernardes prison in Sao Paulo state in the early hours on Monday, but quick police action dispersed the attackers.

Police found two missiles and launchers, assault rifles, a heavy machine gun and ammunition in two abandoned vehicles. Globo television said the missiles were the same kind as those used by Brazil's military, but Takushi could not confirm this. One car contained traces of blood.