PARIS (AP) — President Emmanuel Macron on Thursday called for order and calm, and efforts to address the roots of several days of unrest around France that was sparked by the police killing of a 17-year-old boy.

The police officer accused of the shooting death of teen Nahel Merzouk is in custody on a charge of voluntary homicide, and a judge in Versailles on Thursday rejected his request for release pending further investigation.

“We all lived through an important moment in the life of our nation,” Macron said in the southern city of Pau on the edge of the Pyrenees. He said that France now needs “order, calm, unity. And then to work on the deep causes of what happened.”

He didn’t address what those causes are. The French leader has blamed parents of young rioters and social networks including TikTok and Snapchat for fueling violence that spread to around 500 cities and towns.

Some activists, along with residents of the low-income neighborhoods where the violence began, say the killing was the latest evidence of systematic police brutality and unaddressed racial discrimination in France. Merzouk was of north African origin.