French police have discovered a network of arms caches of the militant Basque separatist group ETA in the south of the country, Spanish police sources said Friday, according to dpa. Two more arms caches were found on Friday, bringing the total to five since Wednesday. The new caches were located in Ferrals-les-Montagnes and Herault in the south-east. Police said they contained a large amount of explosives and munitions, without giving further details. The discovery followed those of two other arms caches in southern France on Thursday. One of them, located in Camplong, held materials to make more than 100 bombs which could be attached to the underside of vehicles, according to the daily El Pais. The same kinds of attacks have killed three Spanish police officers in the Basque region and Majorca this summer. ETA had clearly been planning a long string of attacks, police sources were quoted as saying. The other cache located on Thursday, near Bordeaux, was almost empty. On Wednesday, a cache discovered in the Pyrenees was found to contain 100 kilograms of explosives. The discoveries followed the arrests of three ETA suspects, including the group's alleged logistics chief Aitzol Etxaburu, in the French Alps on Wednesday. Basque police meanwhile removed pictures of imprisoned ETA members from stands at a Bilbao fairground on Thursday, reporting 18 people for praising terrorism, press reports said. The Basque regional government prohibited a separatist demonstration. The regional authorities are trying to corner the entourage of ETA since Patxi Lopez became the region's first clearly pro-Spanish prime minister in May. ETA has killed more than 820 people since 1968 in its campaign for an independent Basque homeland. The group is regarded as a terrorist organization by the European Union and the United States.