Air traffic control operator Luftfartsverket believe the work on Telia’s systems was the 'preliminary cause' of problems according to a report in Dagens Nyheter, though further investigation still needs to be done. The newspaper also reports that some emergency services systems were affected by the problem.
Stockholm airspace was closed for two hours on Thursday after air traffic radar and communications were knocked out by a network tech glitch.
It sparked heavy delays for the remainder of the afternoon and evening, the knock-on effects of which were still felt across Sweden on Friday.
“It's to do with aircraft and staff being in the wrong place because they were not able to get going yesterday. Some companies decided as early as yesterday to cancel as a preventative measure,” Åsa Öhman, press officer at Swedavia which operates Sweden's major airports, told the TT newswire.
Eight departures and eleven arrivals were cancelled at Stockholm's Arlanda airport on Friday morning, including international and domestic flights, while Bromma airport cancelled one departure and one arrival.
Yesterday's issues with data communication in Sweden meant no planes were able to take off, though some were allowed to land. The issue affected most of Sweden, but worst hit were the capital's airports Arlanda, Bromma and Skavsta.
In total 113 flights were cancelled in Sweden on Thursday, of which 85 in Stockholm.
By the end of Thursday the source of the issue was said to be a problem with the network which handles radar and communications equipment at both Arlanda and Bromma.
“We're treating the network failure as an isolated case,” Tomas Olsson, head of the Swedish Transport Agency told TT.
But Sweden's infrastructure minister, Anna Johansson, said she would be meeting with officials to discuss the network failure, as well as investigating possible links to a series of acts of suspected sabotage of telecom masts across Sweden.
READ ALSO: Crisis talks over telecom sabotage in Sweden
The airspace closure came on the same day that an EgyptAir flight with 66 people on board disappeared from radar en route to Cairo from Paris.
In November planes at some of Sweden's busiest airports were grounded for at least an hour after what was described as a powerful solar storm interfered with air traffic control radar systems.
Two closures in a relatively short time period has led to criticism from one aviation expert, who highlighted the costs involved in taking such measures.
“Someone needs to take responsibility and make sure this doesn’t happen again,” aviation journalist and author Jan Ohlsson told TT on Thursday. “If airspace is closed it quickly becomes a really big problem. A break like this for only a few hours costs millions of kronor,” he added.