Six jailed former leaders of the Basque separatist movement ETA have urged the group to abandon the campaign of violence it has carried on for more than three decades.
In a letter written in August and published Tuesday by a Spanish newspaper Diario de Noticias, the six say the armed struggle is no longer working because of harsh responses from the governments of France and Spain.
The letter predates the October arrest of ETA's current leader and seizure of a cache of weapons and explosives, in an event described as the biggest blow to ETA in more than a decade.
Police arrested four more suspected ETA members Tuesday in the northern city of Bilbao.
More than 800 people have been killed in ETA's violent campaign for creation of an independent Basque state in northern Spain and southwestern France.
Some information for this report provided by AP and Reuters.