PARIS (AP) — France is commemorating the fourth anniversary of the Islamic State attacks in Paris.

The attacks on Nov. 13, 2015, left 131 people dead at the country's national stadium, the Bataclan concert hall and bars and restaurants in the city center. They were carried out largely by French fighters for the Islamic State who were sent home by the extremist group.

Wednesday's commemorations are clouded by the possibility that more European recruits for Islamic State may return home soon. Turkey's president has promised to deport foreigners who fought for the group. Since 2015, Turkey has already returned around 250 French citizens, including many children born in Iraq and Syria.

French officials say adults are immediately taken into custody, and that around 500 people are currently imprisoned on terrorism convictions.