PARIS — A man identified as a former boxing pro and suspected of viciously attacking riot police officers with his fists and feet during the latest yellow vest protests in France has turned himself in and was placed in custody on Monday, authorities said.

The suspect, identified by French media as Christophe Dettinger, was filmed beating up police officers Saturday in Paris in videos that went viral on social media and created an outpouring of comments either praising or lambasting the man's actions.

Clashes hit Paris for the eighth straight week of yellow vest protests this past weekend and prompted French Prime Minister Edouard Philippe on Monday to announce the mobilization of around 80,000 police next Saturday. He also said the French government wants to sanction protesters who don't officially register their protests.

The 37-year-old suspect, whose violent outbursts dominated media coverage of the protests, is a former French champion in the light heavyweight category, according to media reports.

"I think he lost it. People can be impulsive; I can be, too," his former coach, Laurent Boucher, told France Inter radio.

In a video message recorded before he surrendered to police, Dettinger acknowledged his wrongdoing but said he just tried to defend himself after he and his wife were tear-gassed by police.

"I have the people's anger inside me. I see all these presidents, ministers and the State stuffing themselves, being incapable of leading by example," Dettinger said. "It's always us, the little ones, who pay. French people, I'm with you wholeheartedly. We need to keep fighting peacefully."

The suspect was involved in at least two fights in downtown Paris on Saturday. On one video, he can be seen aiming several punches at an officer trying to protect himself with his shield on a Paris bridge close to the National Assembly, the lower house of parliament.

In another video , wearing a black hat and gloves, he kicks a police officer lying on the ground.

"What shocked me the most and I think for you it's the same thing, it's to see him hitting the poor policeman when he's on the ground," Boucher said. "And especially when you know he's a boxer. In boxing, you learn not to hit a man on the ground. Never. And he did it."

The suspect was quickly identified but remained on the loose until he turned himself in on Monday.

Dettinger, known when he was boxing professionally as "the Gypsy of Massy," after a town in the southern suburbs of Paris, was praised by many yellow vest protesters, lauding his courage while criticizing alleged police brutality during the protests.

"Even if Christophe Dettinger is not somebody very famous, we can say that a champion is standing by our side," wrote Yasin Aslan, a Facebook user.

The French boxing federation condemned the suspect's "shameful and unacceptable behavior" while Sports Minister Roxana Maracineanu said he had not been a member of the boxing federation since 2013.

"Alongside the French federation, we condemn his attitude which goes against the values of the noble art, and we support the attacked police officers," she said.

Interior Minister Christophe Castaner estimated that about 50,000 people participated in protests around France on Saturday. Police counted about 3,500 protesters in Paris.

The atmosphere was initially calm in the French capital, but turned when some protesters tried to cross the river on the pedestrian bridge not on the official route from City Hall to the National Assembly. The suspect attacked the riot police officer after jumping over a barrier to join other protesters trying to force their way past police ranks.

Police used clubs and tear gas, and then held the bridge in a standoff while violence broke out.

Some confrontations took place in other cities around France, with tear gas fired in Bordeaux and in Rouen in Normandy. Protesters were looking to breathe new life into the yellow vest movement, named after the fluorescent protective gear French motorists must keep in their cars. The protests were launched in anger over fuel tax hikes, but have swelled with broader anger over president Emmanuel Macron's economic policies, considered by opponents to favor the rich.