An IT fault at Germany’s flagship carrier Lufthansa has caused massive flight delays and disruption at airlines across the group worldwide, the company said on Wednesday, adding that the fault cause was still unclear.

“There is a group-wide IT system failure,” a Lufthansa spokesman said.

Photos and videos from several airports across Germany showed chaos with thousands of stranded passengers waiting to be checked in.

Shares in Lufthansa, which also owns Swiss, Austrian Airlines, Brussels Airlines and Eurowings, were down 1.2% at 11.36am South African time.

Lufthansa was working intensively to solve the problem, Bild reported, citing a company spokesman.

Passengers on social media platforms said the failure had forced the company to board planes using pen and paper and that the company was unable to digitally process passengers’ luggage.

Strikes

In a tweet, Lufthansa said: “Currently, the airlines of the Lufthansa Group are affected by an IT outage. This is causing flight delays and cancellations. We regret the inconvenience this is causing our passengers.”