At least 84 people were killed in a shooting attack Friday on a youth camp near Oslo, police said Saturday.
A 32-year-old Norwegian man was suspected of the shootings and also for a bomb explosion in central Oslo that claimed seven lives the same day, Oslo deputy police chief Roger Andresen said.
The death toll at Utoya island, west of Oslo, and the bomb explosion could rise, Andresen added.
Police were to search the waters off the island. Andresen said police had no complete tally of injured or missing.
Andresen said it was too early to discuss a motive or if others were involved.