OSLO, Norway – Killer whales have the highest concentration of man-made toxins of all Arctic mammals tested in Europe because of the oceangoing predators’ taste for fatty fish, according to a study released Monday.

Man-made toxins, such as PCBs, build up in animal fat and become more concentrated as they move up the food chain. Most toxins, often from household products, are carried to Arctic waters by ocean currents, winds or in migratory fish and animals.

Orcas migrate to western Norway’s fjords to feed on herring during the winter. The herring have elevated toxin levels, which then build up in the orca’s blubber, according to the study, funded by the global conservation organization WWF. The Norwegian Polar Institute in the Arctic city of Tromsoe carried out the study.

The study was based on blubber samples taken from 10 male killer whales in 2002 and will continue with new samples taken in November.

Greece: Bomb blast injures three

A bomb targeting Greece’s National Economy Ministry shattered windows and damaged cars in Athens’ main square early Monday, injuring three people, police said. Authorities said the bomb, detonated by a timer, was apparently hidden in a container on the back of a stolen motorcycle at the central Syntagma Square. There was no claim of responsibility.

England: Oil depot still burns

A fire raging at an oil depot in southern Britain sent toxic smoke as far away as France and caused jitters on the global oil market Monday as firefighters struggled today to douse the flames with chemical foam. Authorities said they believe the explosion Sunday at the Buncefield depot north of London was an accident, but will examine other possible causes, including terrorism.

Australia: Board charges surgeon

A medical board in northeastern Australia has charged an Indian-born, American-trained surgeon with unsatisfactory professional conduct for alleged negligence leading to the deaths of 13 patients, an official said today. The Queensland Medical Board said it is seeking a hearing early next year for Dr. Jayant Patel, who is believed to be in hiding in Oregon, over his treatment of at least six patients at the Bundaberg Base Hospital and allegations he lied on his application to practice medicine in Queensland.

Afghanistan: Quake rattles border

A magnitude 6.7 earthquake struck remote northeastern Afghanistan and shook neighboring Pakistan, the scene of a devastating quake two months ago. There were no immediate reports of damage or injuries.

Cuba: Fast begun outside U.S. base

About 25 American activists camping out at a Cuban military checkpoint outside the U.S. naval base at Guantanamo Bay started their first day of a water-only fast Monday to protest the treatment of suspected terrorists detained at the base. Members of the largely Christian group Witness Against Torture are demanding access to the prisoner camp to meet with inmates.