As the unrest in France escalates in the wake of the tragic shooting of a 17-year-old during a traffic stop in Nanterre, clashes between protesters and authorities have reached a critical point. The situation grew even more volatile when a fire broke out at an Olympic pool under construction in Paris. Meanwhile, the government faced significant challenges in restoring order, with over 600 arrests made and at least 200 police officers injured during the tumultuous events of the third night.

Protesters erected barricades, lit fires and shot fireworks at police in French streets overnight. Armored police vehicles rammed through the charred remains of cars that had been flipped and set ablaze in the northwestern Paris suburb of Nanterre, where a police officer shot the teen identified only by his first name, Nahel.

On the other side of Paris, protesters lit a fire at the city hall of the suburb of Clichy-sous-Bois and set a bus depot ablaze in Aubervilliers. The French capital also saw fires and some stores ransacked.

In the Mediterranean port city of Marseille, police sought to disperse violent groups in the city center, regional authorities said. President Emmanuel Macron planned to leave an EU summit in Brussels, where France plays a major role in European policymaking, to return to Paris and hold an emergency security meeting Friday.

Some 40,000 police officers were deployed to quell the protests. Police detained 667 people, the interior minister said; 307 of those were in the Paris region alone, according to the Paris police headquarters. Around 200 police officers were injured, according to a national police spokesperson. No information was available about injuries among the rest of the population.

Schools, town halls and police stations were targeted by people setting fires, and police used tear gas, water cannons and dispersion grenades against rioters, the spokesperson said. Interior Minister Gerald Darmanin on Friday denounced what he called a night of “rare violence.” His office described the arrests as a sharp increase on previous operations as part of an overall government efforts to be “extremely firm” with rioters.

In Nanterre, a peaceful march on Thursday afternoon in honor of Nahel was followed by escalating confrontations, with smoke billowing from cars and garbage bins set ablaze.

In the usually tranquil Pyrenees town of Pau in southwestern France, a Molotov cocktail was thrown at a police office, national police said. Vehicles were set on fire in Toulouse and a tramway train was torched in a suburb of Lyon, police said.

Bus and tram services in the Paris area shut as a precaution, and many tram lines remained shut for Friday morning rush hour.The town of Clamart, home to 54,000 people in the French capital’s southwest suburbs, imposed an overnight curfew through Monday because of the risk of public disturbances. A similar curfew was announced in the town of Neuilly-sur-Marne in the eastern suburbs.

The unrest extended as far as Brussels, the Belgian capital city and EU administrative hub, where about a dozen people were detained during scuffles related to the shooting in France. Police spokeswoman Ilse Van de Keere said that several fires were brought under control.

The scenes in France’s suburbs echoed 2005, when the deaths of 15-year-old Bouna Traoré and 17-year-old Zyed Benna led to three weeks of riots, exposing anger and resentment in neglected housing projects. The boys were electrocuted after hiding from police in a power substation in Clichy-sous-Bois.