AMSTERDAM - More than 60 flights were canceled or delayed at Amsterdam’s Schiphol Airport on Monday due to a strike by ground staff at KLM airline and more action is planned for later this week.

The two-hour work stoppage from 0600 GMT to 0800 GMT was intended to influence ongoing negotiations between trade unions and KLM, the Dutch subsidiary of Air France-KLM, on pay and working conditions.

But trade union association FNV said the airline had not responded and that a second strike was planned at the same time on Wednesday.

“We heard nothing from KLM,” FNV’s airline industry head Jan van den Brink said in a statement. “Therefore we will press ahead with more strike action.”

Talks between the parties over a new collective bargaining agreement began in May, with unions demanding a salary increase of 8% over two years, as well as more full time employees and better working hours.

On Thursday KLM offered a 6-7% pay rise over three years, which unions rejected.

The KLM ground crews service flights for Air France, as well as Delta and other “SkyTeam” allied airlines.