Dozens of ground staff at Geneva Airport headed for strike action on Sunday over a wage dispute with their employer, the Dubai National Air Travel Agency (Dnata) causing flight delays during the busy holiday season.

Dnata personnel, who reportedly handle about a fifth of the traffic through Cointrin Airport, began their strike at 4:00 a.m. (3:00 GMT), the SSP public sector union said on X, formerly Twitter.

The strike was called to demand "dignified working conditions and working wages," it said.

Around 80 strikers gathered in front of the airport wearing bright yellow safety vests and brandishing union flags and posters with messages like: "Dnata is killing me" and "Precarious work means grounded flights".

The airport acknowledged that the work stoppage was delaying flights during the busy Christmas rush.

"Some of the employees of a service provider are on strike today, causing an impact on our operations," it said in a statement, apologizing to passengers for the inconvenience.

Three flights, two of them inter-continental and long-haul, were delayed early Sunday, airport spokesperson Ignace Jeannerat told the ATS-Keystone news agency, adding that they might need to land at other airports.

He said Dnata was scheduled to assist 85 of the 419 flights scheduled on Sunday, a day when the Geneva Airport was expecting 52,000 passengers to travel through.

'Pressure'

Dnata reportedly counts around 600 staff at the airport, who handle various ground operations, including ticketing services and baggage handling, for several international airlines such as British Airways, Air France and KLM.

The union has suggested that around half the Dnata staff have agreed to take part in the open-ended strike.

It said the duration of the stoppage would be evaluated "hour by hour", according to the 20minutes online news site.

Workers are demanding that Dnata, an Emirati airport service provider, hike salaries by 5%.

They also want the company to provide a premium for some physically challenging jobs and additional pay for night and Sunday work, something Dnata has refused to do, union representative Jamshid Pouranpir told 20 minutes.

Dnata has offered to raise salaries by 3% and has also agreed to drop a controversial plan to cut contributions to staff retirement funds, but that has not been enough to satisfy the workers.

Dnata representative Alexandre Koenig told 20 minutes that the company remained "determined to find an agreement", but said it would consider any work stoppage to be "illegal."

SSP meanwhile decried "pressures" exerted by the company, alleging that it has threatened to fire employees who strike, the news site reported.