Thousands of Belgians took to the streets on Thursday in protest over the new government's planned pension reforms in the first day of a multi-day strike that halted all air traffic in the country.

Brussels airport canceled 430 flights on Thursday, a spokesperson said, adding that the disruption to the air traffic sector would last just one day.

Protesters held signs with slogans such as "We're not lemons," and some displayed plaques featuring Latin phrases, a nod to new Prime Minister Bart De Wever's tendency to include Latin quotes whenever possible.

The strike was also expected to disrupt public transport and postal services, with firefighters and military personnel joining the protests as well.

The planned pension reform rewards those who work past retirement age with 35 years of service, while early retirees without 35 years face a penalty. The new system is less favorable for lower-income earners compared to the previous one, which provided a lump sum based on career length.

Flemish nationalist Bart De Wever's government was sworn in on Feb. 3, after eight months of negotiations that resulted in a five-party coalition including right-wing, centrist, and socialist party, Vooruit.

The socialist union had warned that a strike would be called if Vooruit joined the predominantly center-right government.