The rather short notification by the Norwegian National Criminal Investigation Service (NCIS) does not say which specific sites were targeted by the arrested youths, but according to the BBC, local reports seem to indicate that among the targets were the websites of the Norwegian Lottery, the nation's Police Security Service, the financial group DNB, German newspaper Bild and Britain's Serious Organised Crime Agency (SOCA).
"We have arrested the two we think were most important in these attacks, but we still want to talk to more people," said Norwegian prosecutor Erik Moestue. "We know Soca was recently attacked, as well as Norwegian and American sites, and that is one of the things that we are looking into."
If convicted, the arrested youngsters - one 18 years old and the other 19 - could end up in jail for up to six years.
As the investigation is still ongoing, the police declined to comment on the motives behind the attacks - they just confirmed that they were executed over a period of several weeks.
Reading our newsletter every Monday will keep you up-to-date with security news.
Receive a daily digest of the latest security news.