It was sometimes not possible to reach Stockholm University's website during Saturday, while visitors to Gothenburg and Malmö University's websites were met with an error message that the service is not available.
The authority for social security and preparedness (MSB) confirms that university websites were down.
- We know that there is information about that, yes, says Elin Bohman, press secretary at MSB.
However, the authority does not want to go into more detail about what the problem was about.
- We have received information that there has been some type of IT problem with websites concerning universities, but I cannot comment on which ones, what it is about or anything more than that we know about it, says Bohman.
Later on Saturday afternoon, the universities' websites worked again.
Overload attack
The University of Gothenburg (GU) writes on its website that universities and colleges were hit by overload attacks on Saturday, where servers were attacked with a large amount of traffic that led to them becoming unreachable, GP writes.
"The target has been the external websites of the universities", writes GU.
During Friday, 1177 Vårdguiden as well as several hospitals and regions were affected by overload attacks.