“I expect the greatest ethics from our police officers and gendarmes,” Mr. Macron said recently, adding that he did not want to generalize or “harm the credibility and dignity” of French security forces, but that the attitude of officers in a small number of cases was “not acceptable.”

But longtime critics of the grenades were unconvinced that Mr. Castaner’s announcement marked a turning point in the government’s approach to law enforcement.

One group of lawyers representing protesters who have been wounded by the grenades expressed satisfaction that police violence was now “at the heart of public concerns.” But they said in a statement on Sunday that the interior minister’s announcement was a public relations move “in the context of increasing media coverage of police violence.”

“It has been 14 months since we publicly warned Mr. Castaner about the dangerousness of these firearms,” the lawyers said, referring to a letter they had written to the interior minister in the fall of 2018.

That was at the height of the Yellow Vest protests, when violent clashes between demonstrators and the police around the country led to a spike in the use of force by officers, who used rubber projectiles, “dispersal grenades” that spray smaller rubber pellets upon exploding, and tear gas grenades.

Several protesters have lost hands to the GLI-F4 grenades, which were also used in 2014 against environmental activists in western France who had set up camp on the site of a shelved airport project. Other protesters were injured in the feet and legs by shards of the grenades.

The GLI-F4s, which are roughly seven inches long and contain about an ounce of TNT, release tear gas and a strong blast of air upon loudly detonating. They are meant to be used by police officers to disperse aggressive crowds.