The militant Basque separatist group ETA threatened Friday to carry out further attacks in response to the arrest of its most senior leader 10 days ago in France, according to dpa. A communique warned the governments in Madrid and Paris that their "strategy of repression" would lead to a widening of the struggle for Basque independence. "We have no alternative but to continue the armed struggle," the group said in a statement that appeared in the online edition of the Basque newspaper Gara. Francisco Javier Lopez Pena alias Thierry, 49, the ETA political leader, was detained with three of his deputies in the south-western French city of Bordeaux on May 20. The ETA statement also rejected plans by nationalists in the north of Spain for a referendum on self-determination. Calling it "a fraud," it said the plebiscite would not lead to the creation of a separate Basque state along both sides of Spanish-French border. The arrest of Lopez Pena came when police broke into the Bordeaux flat while the ETA suspects were holding a meeting, reportedly to plan attacks. Police seized pistols, munitions, a small quantity of explosives as well as abundant documents and computer materials in the raid. The arrest of hardliner Lopez Pena, who had been on the run from police for 25 years, was regarded as the most serious blow to ETA in years. Lopez Pena ordered an official end to ETA's 14-month ceasefire in June 2007, and launched a violent campaign to make the government "pay" for the failure of peace efforts. Attacks believed to have been ordered by Lopez Pena included the killing of former Socialist councillor Isaias Carrasco two days before the March 9 general elections, and a car bombing that killed police officer Juan Manuel Pinuel a week ago.