Three letter bombs addressed to media outlets in Madrid have been intercepted at a postal sorting office in northern Spain, police said.
They say bomb experts defused two of the devices, which were set to explode when opened, and blew up the third.
The letters were found at the postal centre in Zaragoza, which was evacuated following the alert.
The discovery comes almost three weeks after the 11 March train bombings in Madrid, in which 190 people died.
The letter bombs were addressed to the newspaper La Razon, the radio station Cope and Antena 3 television, Spanish state radio said.