The man charged with carrying out the twin attacks is said to be a former member of an anti-immigration party and the author of blogs criticising multi-culturalism and Islam.
There are website and social media sites bearing Anders Behring Breivik’s name.
Officers refused to speculate on a possible motive for the attacks, saying they had never come across the suspect before.
Bit by bit, a picture is being put together of the man allegedly responsible for the deadliest attack by a lone gunman in recent times.
Police have searched an apartment in a suburb of Oslo.
It is thought to belong to Breivik’s mother.
Norwegian media say the Oslo bomb was made from fertiliser. The suspect is said to own a smallholding near Oslo.
A supply company claims six tonnes of fertiliser – an average order for a farm of that size – were delivered in May.