Police arrested four people today suspected of providing support to armed Basque separatist group Eta.
The arrests, in the Basque province of Vizcaya in northern Spain, formed part of an operation begun in November to dismantle the infrastructure network supporting Eta. The operation is not over, the Interior Ministry said.
Police arrested 20 people in mid-November on suspicion of providing information on targets, recruiting Eta members and organising safe-houses.
Eta has killed almost 850 people since 1968 in a campaign for an independent Basque state carved from northern Spain and southwestern France.
The group, ranked as a terrorist organisation by Spain and the European Union, has not killed in almost two years. Spanish media has speculated an Eta ceasefire could be near after high-profile arrests have weakened the group.