PARIS, March 17 (Xinhua) -- Over 10,000 tons of garbage has piled up in the streets of Paris due to the municipal sanitation workers' strike against the government's controversial pension reform bill, the City Hall said on Friday.

Refuse collectors have been on strike in Paris for 12 days. On Thursday, Prime Minister Elisabeth Borne announced she is activating a special constitutional power to force passage of the pension reform bill, leading demonstrators to set garbage on fire in the French capital.

Striking sanitation workers are also blocking the three waste incinerators in the Paris suburbs.

However, not all the city's 20 arrondissements (quarters) are invaded by garbage, since ten are serviced by private companies.

Mayor of Paris Anne Hidalgo supports the social movement against the pension reform bill. "The claim of the garbage collectors of the City of Paris who legitimately wish not to work two more years is fair," she said at the beginning of the strike.

Her position has sparked controversy in Paris, with many accusing her of contributing to the poor state of hygiene and rats in the city.

French Interior Minister Gerald Darmanin asked Hidalgo to use administrative measures to force refuse collectors and street cleaners to come back to work, but Hidalgo has refused.

The Paris police force has therefore requisitioned municipal workers to "evacuate most of the waste, and ensure that a collection service can be set up." Those who refuse to comply will face a 10,000 euro (10,600 U.S. dollars) fine and six months in prison.

The sanitation workers began striking to express their discontent over the pension reform bill, which will raise the legal retirement age for this category of worker from 57 to 59. Their colleagues in other major French cities such as Marseille, le Havre and Nantes quickly lent their support to the movement.

Elisabeth Borne's announcement she is activating Article 49.3 of the country's constitution, allowing the government to force passage of the pension reform bill without a vote at the National Assembly, has sparked anger across the country.

Spontaneous demonstrations on Thursday saw protestors in Paris using garbage as barricades during clashes with security forces, and setting garbage bins on fire.