Bilbao, Spain: Spanish police on Tuesday arrested nine people from a unit of the Basque separatist group ETA believed responsible for a string of recent bomb attacks.

Interior Minister Alfredo Perez Rubalcaba said the cell's 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.

He said the group was believed responsible for many recent attacks, including the May car bombing of a police barracks in Legutiano during which an officer died.

"We can't say that this was ETA's only command cell, but it clearly was its most active, its most dynamic," Rubalcaba said.

"It is the cell that without a doubt was behind the majority of the violence since ETA broke the truce" with a December 2006 bombing at Barajas airport, the main international one serving the Spanish capital, Madrid.

A Basque police official said the cell is believed responsible for nearly a dozen bomb attacks. 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.