PARIS (AP) — The bar was already high, but the security challenge ahead of the 2024 Paris Olympic Games only grew with a knife attack last weekend that killed a tourist near the Eiffel Tower. Still, the assault at the hand of a suspected Islamic radical, a kind of invisible enemy, left law enforcement undaunted.

The attack quickly raised concern in France and abroad about security for the Games that begin July 26 — in just over seven months. But law enforcement officials appear eager to push back the fear factor and show off a security-ready Paris.

“We are trying to make the invisible risk visible,” said Bernard Bobrowska, inspector general of local police for the French capital. “We are ready.”

Police evaded questions about possible terror attacks from an Associated Press team following a patrol at the Eiffel Tower on Thursday, insisting that all systems will be “go” for the Olympics.

But Interior Minister Gerald Darmanin said after the attack that about a third of suspected radicals under surveillance have psychiatric issues, like the assailant, who had undergone psychiatric treatment.

Hundreds of police already patrol day and night around the Eiffel Tower, which overlooks the Seine River, where an extravaganza will unfold to open the Games.

That high-security zone includes the surrounding sector, where a German-Filipino tourist was killed Saturday night. The suspect, Arnaud Rajabpour-Miyandoab, 26, was taken down with two taser shots after injuring two more people with a hammer, and arrested.

The former director general of the national police, Frederic Pechenard, expressed concern over Olympic security after the knife attack, calling for “an eventual Plan B,” flatly rejected by Sports Minister Amalie Oudaa-Castara. However, she said there could be “adjustments.”

Safety worries extend beyond France.

The Dutch government upgraded its travel advisory Friday. “Throughout France, and especially in Paris, be aware of possible new violent attacks,” authorities warned. Security is at a maximum with a “zero delinquency” plan in place around Olympic sites, which include the Eiffel Tower and the Seine, according to officials.