A spokesman from the Basque Interior ministry has confirmed that the rucksack bomb used in the attack on the offices of the El Correo Basque daily contained 5kg ammonal and was detonated with a timer.

It was left near the main printing press towards the back of the building, where it caused a substantial amount of material damage.

To date, ETA has not taken responsibility for the bombing, nor was any prior warning given.

ETA blamed for Basque newspaper office attack
By: thinkSPAIN
Sunday, June 8, 2008

A bomb went off at 3am last night without prior warning outside the offices of the El Correo Basque daily newspaper in Bilbao, where around fifty people were working on the Sunday edition. None were injured, and they were able to resume work by 5am.

The explosive device has caused substantial damage to the back of the building, and also affected a sports clothing company housed in an adjoining unit on the Torre Larragoiti industrial estate in Zamudio.

The paper belongs to the Vocento group that has been targeted on a number of previous occasions by radical separatists - the most serious of which occurred in San Sebastián in May 2001, when ETA murdered the financial director of El Diario Vasco, Santiago Oleaga.