Internet difficulties during the opening ceremony of the 2018 Winter Olympics in South Korea have prompted officials to investigate the possibility of a cyberattack.

Organizers noticed suspicious signs before and during the ceremony, the New York Times reported. A spokesman for the Pyeongchang Organizing Committee said technical issues affected some of their "non-critical systems" for a few hours Friday night.

The Times reported that the stadium’s wireless service stopped working at the beginning of the ceremony, inhibiting reporters and attendees from posting on social media.

According to South Korea's Yonghap News Agency, internet-based telecasts were disrupted, and some people who bought tickets online for the opening ceremony said they couldn’t print their tickets.

Nevertheless, the supposed attack did not disrupt the event or jeopardize the safety of the athletes or other attendees. A cybersecurity team was reportedly assisting with the investigation.

The website normalized Saturday morning, Yonghap reported. Olympic committee organizers said the origins of the attack remained unknown.