Police found a second cache of bomb-making materials this week believed to belong to the armed Basque separatist group ETA, the Spanish Interior Ministry said Tuesday, according to AP. Authorities found the latest materials Tuesday in the northern Navarra province, after finding another cache on Monday. Both discoveries followed the arrest on Sunday of two suspected ETA members, the ministry said, adding that police were searching for another two suspects. ETA has killed more than 800 people since the late 1960s in its campaign for an independent Basque homeland in northern Spain and southwest France.