Pamplona, Spain - Police in northern Spain have smashed a cell of the underground Basque separatist group ETA and have arrested four suspected terrorists.

Sources close to the investigation said three men and a woman had recently established the cell in the Navarra region and had planned to carry out an attack from the neighbouring Basque region.

Three suspected ETA members were arrested in Navarra's capital Pamplona. The fourth suspected ETA member was detained in the southern port city of Valencia.

One of the suspects was previously arrested in connection with ETA activities. The others have no known links to terrorist activity.

ETA is listed as a terrorist organization by the European Union and the United States. dpa hk bve wjh