Armed Basque separatist group ETA said on Tuesday it will end its 15-month-old ceasefire at midnight and warned the Spanish government of new attacks "on all fronts".
In a communique sent to Basque media, the rebels said they were calling off the truce because of "arrests, tortures and every type of persecution" by the Socialist government, which tried unsuccessfully to negotiate peace last year.
ETA, which has been fighting for independence for the Basque territories for four decades, declared a ceasefire in March 2006 and had insisted that it still held despite killing two people with a bomb at Madrid airport in December.
The government of Prime Minister Jose Luis Rodriguez Zapatero started exploratory peace talks in mid-2006, but broke them off at the end of the year after the airport bomb. At the time, ETA said it had not meant to kill anyone and was only seeking concessions in peace talks.
"ETA wishes to announce that it is abandoning its permanent ceasefire and has decided to act on all fronts in defence of Euskal Herria," the group said, using the Basque language name for the Basque Country. Zapatero said the ceasefire had already been broken in December by ETA, which also called off an earlier truce in 1999.