Just terrible. From the BBC:
A massive bomb blast has hit government buildings in the Norwegian capital Oslo, killing at least seven people and injuring several others. PM Jens Stoltenberg described the situation as “very serious”. The bomb was followed by a fatal shooting incident near Oslo at a youth meeting of the Labour Party, which Mr Stoltenberg leads. Norwegian media said at least four people were killed when a man opened fire indiscriminately. Police said the suspected gunman had been arrested, TV2 reported. No group has said they carried out the attacks but police say they believe them to be linked.