Brussels - A national strike was crippling Belgium on Monday, with flights grounded, trains at a standstill and businesses across the country blocked by picket lines.
It is the fourth Monday in a row that work stoppages have been held in Belgium to protest labour and social measures pledged by the new government of Prime Minister Charles Michel. The small European country is home to EU institutions and the Nato military alliance.
Belgian trade unions say they are against austerity, for instance opposing plans to introduce pension reforms and end the automatic indexation of salaries. But Michel has argued that reforms are necessary to create more jobs and provide social services.
"We are here to say that we want a social Europe and not dumping," Bruno Antoine of the CSC union told the Belga news agency, as his members worked to hamper traffic on the E411 highway in the south of the country.
Roadblocks were also being erected in the capital Brussels to snag vehicle traffic there.
"This is not the end of the social conflict in Belgium," predicted fellow CSC representative Dominique Wilkin. Other unions have also threatened to continue with strikes in January if their demands are not met.
The Zaventem international airport in Brussels was paralysed on Monday, with all flights cancelled and the Belgian airspace shut down. Some 600 flights were affected, Belga wrote.
No public transport was available in Brussels and no trains were running on the Belgian network, which has important international connections to neighbouring Germany, France and Britain.
Rail disruptions are also expected on Tuesday, after signal cables were set on fire in Brussels. The railway workers' CGSP union denied any involvement and denounced the incident as "sabotage", telling Belga that it "discredits today's legitimate [labour] action".
The strike was also affecting hospitals in the country and international companies such as Audi, Ikea, Coca-Cola and ArcelorMittal, according to Belga.