The boys, aged 16 and 17, are accused of planning to kill the headmaster of the Enskede Gård Gymnasium, Rolf Ödén. The pair were arrested separately on Friday morning. At least one of the boys was at home with his family when police called. Neither arrest was dramatic, police say.
Police are treating the crime as conspiracy to murder. To gain a conviction for conspiracy to murder, prosecutors would have to show that the accused had planned and prepared to carry out the killing.
"We want to see what the investigation brings up and find out what substance there is to these suspicions. The first interviews have been held, but I cannot comment on the background to the suspicions," said Karin Solberg of Stockholm Police.
According to Öden himself the boys had made a serious threat against the school and against him personally. They were allegedly inspired by the events in Jokela on Wednesday and by earlier school massacres such as the 1999 shootings at Columbine High School, Colorado.
"They had spoken about and glorified Columbine High and what happened in Finland. They are fixated on guns, and that has made us react in the past, but previously there were never any threats," Ödén said.
Ödén said he felt obliged to call the police on Thursday after signs that the boys' behaviour had become threatening.
"I think one should be frank. It is my duty to investigate all possible threats and violations," he said.
He said that the atmosphere at the school on Friday was calm.
"As I've walked around, everything is calm and collected. No panic and nobody staying at home as far as we know. I have informed the staff and they have informed the pupils," he said.
The boys are to be allocated public defenders. Police say they will interview them further over the weekend.