Four suspected members of an Islamist militant network have been arrested in the Spanish territory of Ceuta, which borders Morocco.
Two Moroccans and two Spaniards were arrested in raids on two properties by Moroccan and Spanish police.
Spanish police said the men were “prepared and willing” to carry out a terror attack in Spain.
Some 50 suspected jihadists have been arrested by Spanish police over the past year, the ministry has said.
Spanish Interior Minister Jorge Fernandez Diaz said the men arrested on Saturday were two pairs of brothers who were “highly radicalised and highly trained”, Reuters news agency reported.
A pistol, combat uniforms, machetes, number plates, documents and computer equipment were seized in the dawn raids, the interior ministry said.
Police said the men had a “similar profile” to those who carried out the recent attacks in Paris, and that they had been inspired by internet propaganda by the jihadist Islamic State group.
The interior ministry made no link between the latest arrests and continuing investigations into suspects linked to this month’s attacks in Paris and intercepted plots in Belgium – some of whom are said to have travelled to Spain.