PARIS, France (AFP) — Paris Olympics organisers said on Friday they were experiencing problems linked to the global IT outage, causing difficulties in handing out accreditations to athletes and officials arriving for the Games.

Airlines, banks, TV channels and other business across the world have scrambled following one of the biggest computer crashes in recent years, caused by an update to an antivirus programme.

“Like a lot of organisations, we suffered this global Microsoft outage,” chief organiser Tony Estanguet told reporters, a week before the opening ceremony of the Olympics.

“All of our servers were affected this morning.”

Estanguet added critical IT systems had not been hit but “for operations on the ground, to welcome new athletes, to welcome all the delegations, to issue accreditations, it slows down our operations.”

Thousands of athletes have begun flying into Paris ahead of the opening ceremony, with the newly built Olympic village opening its doors on Thursday.

The organising committee said in a separate statement the impact of the outage was “limited” overall but it had also complicated the distribution of uniforms to the 45,000 volunteers for the July 26-August 11 event.

The IT problems have not affected Paris airport operator ADP, but “the arrival of some delegations has been impacted by delays to their flights,” the organising committee added.

Paris is putting the finishing touches to preparations for the global sporting extravaganza, the first Olympics in the French capital in a century.

The venues are on track, the weather has brightened up after months of rain, and the water quality in the Seine has improved, making outdoor swimming events in the river possible after months of suspense.

New data released on Friday showed the river was clean enough to swim in on six out of seven of the last days.

“We weren’t necessarily expecting an IT outage a few days before the start of the Games,” Estanguet said.

French authorities are on high alert for cyberattacks; however, either from criminal groups or nation-state actors, with Russian hackers viewed as a particular risk.

“It’s absolutely certain and inevitable that ransomware attacks will occur during the Games,” France’s cybersecurity agency Anssi said on Thursday.

“Statistically, there is a high chance that ransomware attacks will affect actors who will be involved in the Games.”