PARIS (AP) — A resurgence of anti-police violence has emerged in the long-troubled towns around Paris, signs that lawlessness still simmers in the French urban hotspots that exploded in three weeks of rioting in 2005.

Unrest on Saturday night in Chanteloup-les-Vignes and recent flare-ups in other tough neighborhoods west of Paris have not matched the intensity or destructiveness of the unrest that spread to hundreds of towns in 2005. But French authorities are alarmed because the violence appears pre-planned, with ambushes deliberately set to target police.

Police union officials suspect that rival gangs from different tough neighborhoods are competing for bragging rights in their attacks on police and are reveling in the media coverage that their violence is generating.