PORTLAND, Ore. (KOIN) — Alaska Airlines announced on Monday another 39 flights were canceled nationwide after pilots picketed over the weekend.

The airline says about 6,000 guests will be impacted by the most recent cancellations.

As of 11 a.m. Friday, three Alaska Airlines flights headed in and out of Portland International Airport had been nixed.

On Friday, pilots took to the picket lines over contract negotiations across five major cities, including Portland. About 250 pilots and other personnel from Alaska Airlines reportedly participated in the picket at PDX.

A spokesperson with Alaska Airlines told KOIN 6 News that a shortage of pilots forced them to cancel some flights over the weekend.

Pilots with the airline allege the company did not plan for increased travel demand, nor did the airline try to attract new pilots and keep its current workforce. Further, the pilots say Alaska Airlines received $2.3 billion during the pandemic to help retain its employees.

The airline warns more cancellations are possible.