Law enforcement officials told ABC News there were two blasts at the Norwegian capital and Norwegian news reported at least two people were killed. Several more were injured.
The prime minister, whose office is in the building, survived the blast, a government spokesperson told The Associated Press.
Pictures, posted on Twitter, show several buildings with windows blown out. Multiple tweets described people bleeding in the streets. Law enforcement officials said
No group has publicly taken responsibility for the blast and a U.S. counter-terrorism official told ABC News there is no indication yet of motive or suspects. A senior U.S. diplomat in Oslo said they believe all U.S. personnel in the country are safe and accounted for.