A traffic accident prompted the closure of the Svartdal Tunnel on the E6 highway in Oslo. Following the initial incident, a motorcycle collided with the road barrier positioned outside the tunnel entrance. Authorities have closed the tunnel to all traffic while assessing the situation and clearing the scene. The extent of any injuries sustained in either incident is currently unknown. Motorists are advised to seek alternative routes and expect delays. The tunnel remains closed as of this reporting, with no immediate estimate for reopening provided. Further updates will be released as information becomes available.