Swedish government websites were attacked by hackers on Monday, with suspects to most probably be supporters of WikiLeaks founder Julian Assange.
The websites of the Swedish government, Armed Forces and the Swedish Institute were among those experiencing problems.
The denial-of-service attacks, in which websites are overwhelmed with bogus traffic, lasted some hours during Monday.
An unidentified group urging Sweden to take its "hands off Assange" (WikiLeaks founder) claimed responsibility on Twitter.
Assange has been sheltering at Ecuador's Embassy in Britain in an effort to avoid extradition to Sweden. Swedish prosecutors want to question Assange over alleged sex crimes.