Hundreds of passengers were stranded at Helsinki’s main airport Wednesday as a number of flights were cancelled or delayed a day after Finnair’s technical staff launched a week-long strike.

Several domestic and regional flights were grounded and long-haul flights to Beijing, Nagoya and Toronto were among those cancelled, Finland’s national carrier said.

“Stranded customers are entitled to have their tickets refunded,” Finnair spokeswoman Laura Varja told AFP, adding that affected passengers could also be moved to other carriers or reschedule to a later date.

“At the moment we are unable to predict the strike’s impact on future flights, but we expect a few cancellations and delays,” she said.

Some passengers at Helsinki Vantaa airport said they were worried about how the week-long strike would affect them.

“I am quite nervous about my return flight next Monday,” Pirjo Peltola, a passenger en route to Prague, told the STT news agency.

The strike broke out Tuesday over Finnair’s decision in April to outsource its engine and component services to Swiss company SR Technics at the cost of 280 jobs.