Suspected members of the Basque separatist group ETA detonated four small bombs in northern Spain on Sunday, injuring three people, officials said.

Suspected members of the group targeted businesses in four towns of the Basque region, where an explosion occurred around 3 AM at a chemical plant.

Two policemen and a security guard were taken to hospital after inhaling toxic fumes from leaking acid, said regional police. The victims were later discharged from hospital after treatments.

Spanish Interior Minister Jose Antonio Alonso vowed to take resolute action, saying security forces would resume fighting against ETA until its "disappearance".

The Basque regional government condemned ETA for the renewed attack, saying "all the data" involved point to the group, which for decades has killed some 800 people in its campaign for Basque independence.

Police definitely held ETA responsible, citing the composition of the explosives. They said the devices were made of 1.5 kg explosives with timers, typical of the armed group in extortion of money from businesses.

There has been a letup in deadly attacks by ETA since May 2003,when a police car was exploded in Sanguesa near the Basque region, killing two officers.

Just before the blasts, many expected a truce to be announced by ETA which had suffered heavy losses in recent years. The government said in the past year alone more than 170 ETA members were arrested.
 
On Saturday, the government said it was ready to negotiate with ETA and seeking parliamentary support for talks if the group renounced violence.

(Xinhua News Agency May 16, 2005)