Norwegian police say a suspicious suitcase found on a bus at the central station in the capital, Oslo, poses no danger.

Railway officials said parts of the station were evacuated Wednesday after the abandoned bag was discovered in an area where buses depart for the airport.

Norway is on high alert after a bombing and massacre last week that killed 76 people.

Police on Tuesday began releasing some of the names of those killed — three who were killed in the bomb blast in Oslo and one in the shooting rampage at an island youth camp.

The defense lawyer for the Norwegian man who confessed to the attacks, Anders Behring Breivik, says the case suggests his client is insane.

At a news conference in Oslo Tuesday, defense attorney Geir Lippestad told reporters it was too early to say if Breivik would plead insanity. He said Breivik is not aware of the death toll nor of the public response to the massacre.

While Breivik has admitted responsibility for the attacks, he has pleaded not guilty to the terrorism charges, claiming he acted to save Europe from what he says is Muslim colonization.

Police Tuesday detonated a cache of explosives found at a farm Breivik rented about 160 kilometers north of Oslo. Breivik reportedly used the farm as a cover for ordering the six tons of fertilizer he used to make his bomb.

In Washington, U.S. President Barack Obama visited the residence of the Norwegian ambassador to personally offer his condolences for the victims of the twin attacks. Accompanied by Vice President Joe Biden, Mr. Obama said he was heartbroken by the tragic loss of life, and reassured the Norwegian people that the United States stands with them.

Mr. Obama on Saturday condemned the “senseless” attacks, calling the tragedy a reminder that the world has a stake in stopping such acts of terrorism.

Breivik's attorney said Tuesday that his client told him he took drugs to be “strong, efficient, awake.” The lawyer added Breivik claims to be part of an anti-Islam network that has two groups in Norway and several more abroad. But Norwegian police and researchers have cast doubt on such claims. Police say they believe Breivik acted alone.

Earlier, Norway Justice Minister Knut Storberget praised police for their response to the attacks Friday, saying officers did “fantastic” work.

His comments follow criticism in the media about how long it took police to reach the camp on Utoeya Island, where Breivik is accused of killing at least 68 people. Police have said it took more than an hour for officers to get to the site.

The suspect's father, retired diplomat Jens Breivik, told reporters in France that he feels shame and wishes his son had killed himself instead.