Norway’s national news agency has said police are investigating whether a second suspect was involved in the shooting spree on the island of Utoya.
Police have arrested one man on preliminary charges in the massacre and a bombing in Oslo hours earlier which has resulted in 91 deaths in total.
NTB reported that witnesses told police two people were involved in the shooting on Utoya island. The agency said police are looking into it.
The agency said that the second man apparently wasn’t disguised in police uniform.
A Norwegian newspaper also reported that the main suspect, Ander Breivik, bought six tons of artificial fertiliser some 10 weeks before the attacks.
Verdens Gang newspaper cited Oddny Estenstad, a spokeswoman for agricultural material supplier Felleskjopet, who said the products were delivered to the suspect on May 4.
Artificial fertiliser is highly explosive and can be used in homemade bombs.
Mr Estenstad said police were alerted to the purchase after it emerged the man was suspected of the deadly attacks.
And in a further development police detained a man outside a hotel where Norway’s prime minister was meeting families of shooting victims. The man told reporters he was detained “because I have a knife”.
The man, who appeared to be around 20 years old, was standing outside the hotel next to reporters when two officers apprehended him and led him to a police car.
The man told reporters he was a member of the Labour Party’s youth wing and was carrying a knife “because I feel unsafe”.