"The planned nationwide strike in Belgium on Monday, December 15 will directly affect flight operations in and out of Brussels airport (BRU)," a Jet statement said.
The airline cancelled flight 9W-228 on the Mumbai-Brussels-Newark sector and 9W-227 on Newark-Brussels route on December 14 and Brussels-Mumbai on December 15.
Delhi to Toronto flight 9W-230 and Toronto-Delhi flight 9W-229 would be re-routed via Paris on that day, it said.
The airline is providing options like rescheduling of flights, postponing travel dates upto ten days from the original date without any fees or refunds without cancellation, to its passengers who have booked their travel through Brussels on December 15 and now wish to change their flight plans.
Belgium has been witnessing a series of strikes during the past few weeks which have disrupted several services, including ship movement, road, rail and air transport, with unions protesting austerity measures announced by the country's new government.
The series of regional strikes would be followed by a nationwide strike on December 15, reports from Brussels said.
Earlier, due to strike by major trade unions in Belgium on December 8, Jet had cancelled four flights to and from Brussels, as also to Newark and Toronto.