The Norwegian Football Association said in a statement that all top-flight games had been postponed and would be rescheduled.
A pair of attacks killed approximately 90 people in and near the capital of Oslo, beginning with the bombing of Prime Minister Jens Stoltenberg's office that killed seven people early Friday.
Not long afterwards, at least one man dressed as a policeman gunned down scores of teenagers attending a Labor Party youth camp on the small island of Utoya near Oslo, killing at least 84 of them, Views and News from Norway reported.
The gunman was wearing a police uniform and used a handgun, shotgun and an automatic weapon, the report said.
An hour after the shooting started, police arrested 32-year-old Anders Behring Breivik, the report said. They later found explosives on the island, the report added.