Swedish authorities grounded planes from Stockholm and the western city of Gothenburg on Thursday due to computer problems that affected network communications.

No planes were being allowed to take off from Stockholm airports and those in the air were being called down, the Air Traffic Authority said.

"No planes are allowed to take off at the moment and we're taking down the planes in the air," said spokesman Per Froberg. "It's a network communications problem."

He declined to give further details.

Air traffic control officials at Bromma airport told daily Dagens Nyheter that the incident was not terror related.

Arlanda is about 40 km north of Stockholm. Swedavia, the company that operates the airports, said 23.2 million passengers used Arlanda in 2015, while 81 airlines use the airport.

Last year a solar flare briefly brought down radar at Stockholm's airports as well as Gothenburg for several hours, leading to flight delays. - Reuters