The radar system that controls the airspace at Oslo Airport Gardermoen and Stavanger Airport Sola is located in Norway, reports VG. 

– It is the so-called NATCOM NATC system that is down, says press officer Øystein Løwer at Avinor, to the newspaper.

All departures from the airports have been stopped and incoming flights are being redirected. 

– We don't know how long it will last. Troubleshooting is ongoing and we will publish information continuously on our websites, says Øystein Løwer.

Source: Aftonbladet.se