KRASNAYA POLYANA, Russia (AP) — Thick fog lingering over the mountains Monday caused the biggest weather disruptions of the Sochi Olympics so far, with a biathlon race and a snowboard event both postponed until Tuesday.

The fog rolled in over the mountains in Krasnaya Polyana on Sunday night and was still shrouding some of the Olympic skiing venues in a cloud-like mist by late Monday afternoon. That prompted organizers to call off the men’s biathlon mass-start race and men’s snowboardcross almost simultaneously.