Four explosions have occurred near a power station in Spain's northern Basque country. The power station is 50% owned by the ESB. The other 50% is owned by Osaka Gas, one of the biggest gas companies in Japan.

A spokesman for the ESB has confirmed that the Amorebieta plant has been evacuated and a full security operation is underway. The plant, which is in the final stages of commission, is manned mostly by a local Spanish workforce.

The blasts caused no damage to the power station. The explosions were reported to have occurred in scrubland within the perimeter of the plant, but not in any of the buildings.

Spanish radio said there were no injuries.

A caller to a Basque newspaper had warned earlier that four bombs would explode near the power station at Amorebieta, in the Basque country, police said.

The warning, about half an hour before the explosions, gave police time to clear the area.

ETA staged a series of bombings on electricity lines last summer in an apparent attempt to disrupt Spain's infrastructure.

ESB International has built the plant from scratch as the first foreign operator in the Spanish market and it will come on stream later this year. Construction has been underway since February 2003 with up to 700 people working on the site as it was built.

ESB is to manage the operation and maintenance of the power plant for an initial 20 year period.