Iberia Express, the low-cost arm of Spain's national carrier, cancelled eight domestic flights Sunday as cabin crew launched a 10-day strike for higher wages amid soaring inflation.
The walkout, which will run from August 28 to September 6, is expected to involve a total of 92 cancellations affecting more than 17,000 passengers, a spokeswoman for the USO union said.
The stoppage comes as Spain's airline sector struggles with rolling strikes by staff at budget rivals EasyJet and Ryanair.
By midday (1000 GMT), eight flights had been cancelled but there were no delays, a USO statement said, indicating 1,500 passengers had been affected.
Iberia Express confirmed eight "preventative cancellations", saying in a statement it had arranged alternative flights or transport for 84 percent of affected passengers, with the rest opting for a refund or vouchers.
On Friday, the airline had announced it would cancel 24 domestic flights during the first three days of the walkout, affecting some 3,000 passengers.
It did not immediately say how many more flights would be axed beyond those initial dates.
USO and the SITCPLA union are calling for a salary increase to compensate for inflation, which in July hit 10.8 percent.
Iberia Express connects Madrid with about 40 cities across Europe.
Spain's national carrier Iberia is owned by IAG, which also owns British Airways and Ireland's Aer Lingus.