No planes are allowed to take off from Stockholm airports and those in the air are being called down due to a network communication problem, the Air Traffic Authority said on Thursday."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.

A spokeswoman for Sweden's Civil Aviation Administration Asa Ohman says no flights have been taking off from Stockholm's Arlanda and Bromma airports or from Landvetter airport in Sweden's second largest city, Goteborg, since 12 p.m. (1000 GMT). Planes have still been landing at those airports.

Ohman says the problem is "a technical issue with a radar system that we are working on."

It was not clear when the problem, which was causing delays but no cancellations, would be fixed.