The U.S. Department of Homeland Security launched an operation Wednesday to arrest undocumented immigrants described as "criminals" in New Orleans, accusing the city's Democratic authorities of not cooperating with immigration police.

President Donald Trump reiterated Tuesday his intention to send National Guard troops to New Orleans, in the southern United States, as he has already done in Los Angeles, Washington, D.C., and Memphis, each time against the advice of local Democratic officials. He claims these reinforcements are necessary to combat crime and support Immigration and Customs Enforcement (ICE).

Donald Trump said he received a call to that effect from the Republican governor of Louisiana, Jeff Landry. "He asked for help in New Orleans and we will be there in about two weeks," he assured.

The operation "will hunt down the worst of the worst in New Orleans," Homeland Security Secretary Kristi Noem said on X.

The ministry stated in a press release that the operation targeted "illegal criminal immigrants at large," calling into question the sanctuary policy implemented by the Democratic authorities of New Orleans.

These so-called "sanctuary" policies adopted by many Democratic states and cities consist of strictly limiting collaboration between local law enforcement and ICE agents, particularly to protect undocumented immigrants from threats of deportation.

An AFP photographer on the scene witnessed several arrests, some of them tense, as part of this operation.

Donald Trump has made the fight against illegal immigration an absolute priority, referring to an "invasion" of the United States by "criminals from abroad" and communicating extensively about the deportations of immigrants.

His government systematically equates crime with illegal immigration and claims to be targeting "the worst of the worst" immigrants who have committed crimes.

But according to unpublished ICE statistics obtained by experts at the libertarian-leaning Cato Institute, only 5% of people detained by immigration police since the start of the fiscal year on October 1 have been convicted of violent acts and nearly 70% have no convictions.

The Department of Homeland Security disputes these figures, arguing that "70% of ICE arrests involve undocumented criminals accused or convicted of offenses in the United States."

In Chicago, in the north of the country, which was targeted by a similar operation, a federal judge ordered in November the release on bail of more than 400 people arrested by ICE who did not pose a security risk.

This decision has been suspended, as the government has appealed. The hearing before the Court of Appeal was held on Tuesday, but no ruling was immediately issued.