Around 100,000 Belgians marched through central Brussels on Thursday in protest at the new government's proposed reforms and cost-cutting measures, the first in a series of demonstrations and strikes planned over coming weeks.

Belgium's centre-right government, installed only a month ago, has pledged to raise the retirement age and limit scope for early retirement, cancel an inflation-linked wage hike due next year and cut the health and social security budgets.

Unions estimated that around 120,000 workers, from dockers to metalworkers, as well as students, had gathered to protest in the Belgian capital. Police put the number at 100,000.

The unions plan a series of regional strikes every Monday starting Nov. 24, culminating in a national strike on Dec. 15.

For Thursday's march, rail operator SNCB said it had sold 80,000 tickets in advanced group bookings for travel to Brussels and had laid on 15 additional trains. Unions had also booked 500 buses to get protesters from all over the country to the capital.

Otherwise, public transport in Brussels was severely restricted. Buses and tram services in other Belgian cities were also reduced.

A demonstrator confronts riot police in central Brussels November 6, 2014. Tens of thousands of public and private sector workers, employees and trade union members demonstrated over austerity measures to be taken by the new Belgian government. [Photo/Agencies]