Spanish police on Tuesday arrested eight suspected members of a unit from the Basque separatist group ETA believed responsible for a string of recent bomb attacks.

The cell’s alleged leader, Arkaitz Goikoetxea, was among those arrested in raids in the towns of Getxo and Elorrio, close to the northern Basque port city of Bilbao, a Basque police spokesman said.

The official said the cell is believed responsible for nearly a dozen bomb attacks, including one on a Civil Guard barracks at Legutiano in May during which an officer died. The spokesman said some of the detainees’ fingerprints were found on the car exploded at Legutiano.

The official spoke on condition of anonymity because of police regulations.

The spokesman said the cell was one of ETA’s most active since the separatist organization broke a cease-fire in December 2006 after it grew frustrated at a lack of progress in peace talks with the government.

The cell also is blamed for attacks on two other police stations, two court houses and two party political offices.

The eight arrested were said to be in their early 20s.

The arrest operation was overseen by Spain’s leading anti-terror judge, Baltasar Garzon, who was present for the detention of Goikoetxea.

Interior Minister Alfredo Perez Rubalcaba was to give details of the raids later Tuesday.

The arrests came two days after ETA claimed responsibility for five small blasts in holiday resort towns across northern Spain.

ETA _ considered a terrorist group by Spain, the EU and U.S. _ has waged its armed campaign for an independent Basque state in northern Spain and western France since 1968. It is blamed for killing more than 820 people, including security force members, politicians and civilians.

It broke the cease-fire with a bomb in December 2006 that killed two people, then officially ended the cease-fire the following June. Since then, it has killed three police men and a local Basque politician.

The northern Basque region is one of 17 semiautonomous regions in Spain and among the strongest economically. It has its own language and culture and is home to strong nationalist sentiment.