PARIS: Thousands of protesters marched under tight security in eastern Paris on Saturday after French labor unions, left-wing political parties and civil rights groups called for “floods of people” to oppose the pro-business policies of President Emmanuel Macron.

Marches and rallies were also held in dozens of other French cities as part of the joint action against Macron’s economic policies that organizers consider “brutal” and imbalanced.

At the Paris event, Philippe Martinez, head of leading French union CGT, advised the president to “look out the window of his palace to see real life.”

Police estimated that 21,000 people took part in the Paris protest, while CGT put the number at 80,000.

More than 1,500 police officers were mobilized in the French capital to prevent activists not associated with the official protest from disrupting the march and causing damage, which has happened during previous recent demonstrations.

Police said they detained 39 people before and after the march. Most were pre-emptively taken in for questioning after officers searched their bags and found “equipment” that could be used to cause damage or to hide their faces.

The opposition was particularly denouncing a Macron-led overhaul of labor rules that would reduce worker protections and laws increasing police powers.