French authorities on Tuesday ordered an investigation into the forceful removal by police of a camp of migrants in central Paris that prompted outrage over the "brutal" tactics used.

Interior Minister Gerald Darmanin said he had agreed to a proposal by the Paris police chief to immediately refer the issue to the National Police Inspectorate General (IGPN), which investigates officers' conduct.

The government is already facing a storm of criticism over new security legislation being debated in parliament that opponents say will erode the accountability of the police.

Officers used tear gas to break up the Paris camp, which was set up to protest against earlier forced evacuations of hundreds of migrants from other camps.

Volunteers had helped erect about 500 blue tents at Republic Square that were quickly filled by migrants, the majority from Afghanistan.

Police arrived shortly afterwards to remove the tents, sometimes with people still inside, in the face of protests from migrants and jeers from activists.

- 'Lamentable show' -

"They are too violent," said Shahbuddin, a 34-year-old Afghan, crying after being evicted. "We just want a roof."

Police later used tear gas and rough tactics, with videos posted on social media showing one officer tripping a man as he ran, and another officer slamming into a man who tried to intervene.

The controversy comes a week after migrants were evacuated from makeshift shelters in the northern suburb of Saint-Denis, including some who were not provided with alternative shelter.

"The state has made a lamentable show," Ian Brossat, a Paris deputy mayor in charge of housing, told the press.

CFDT trade union chief Laurent Berger told France 2 TV that the actions of the police were "scandalous and astounding."

"People occupy a square peacefully with tents, simply because they have a housing problem, they are not harming anyone. And there is this intervention which is totally disproportionate," he said.

After receiving a report from Paris police chief Didier Lallement confirming "several unacceptable facts", Darmanin -- who had earlier described some of the images of the camp's removal as "shocking" -- said that the IGPN would submit its findings within 48 hours.

Paris' Socialist mayor Anne Hidalgo wrote a letter to Darmanin denouncing the "brutal and disproportionate use of force" by the security forces, which she said was "unfortunately not without precedent" in the city.

And France's ministers for citizenship and housing, Marlene Schiappa and Emmanuelle Wargon, issued a joint statement saying migrants must be treated with "humanity and solidarity."

- 'Didn't vote for this' -

Paris is a key stop-off point on the European migrant route with thousands passing through, often heading to England.

Encampments repeatedly sprout up around the city only to be torn down by the police.

The latest camp removal came as the government is pushing a security law through parliament that would restrict the publication of photos or videos of police officers' faces -