The boys, 16 and 17 years old, were arrested in Stockholm early Friday after police received information that they were planning murder, police spokeswoman Karin Solberg told the Associated Press.
One of them was also suspected of making threats, she said.
Solberg declined to comment on the type of information police had received, or to whom the threats had been directed, referring to the suspects' protection as minors.
According to Swedish daily newspaper Dagens Nyheter, the two boys - students at a high school in a Stockholm suburb - had threatened to kill the school principal and the janitor.
"There is a threat against me which ... has been directed toward me personally, but I don't want to get into it any more than that," Rolf Oden, principal at the Enskede Gards Gymnasium, told the newspaper.
He declined to give details on the threats.
"These two boys are clearly inspired by the events in Finland," he said.
On Wednesday, an 18-year-old boy opened fire in his high school in southern Finland, killing eight other people and himself.
Oden said the boys in Stockholm "had a fascination with guns and these type of events."
Police spokeswoman Solberg said the arrest was undramatic and the boys were being interrogated.