PARIS (AP) — Unusual spray-painted images and messages with references to Ukraine appeared on the streets of Paris on Friday as Ukrainian President Volodymyr Zelenskyy met with U.S. President Joe Biden in the French capital.

It was unclear who sprayed the graffiti that has appeared on several buildings in central Paris near the Parliament complex and various government ministries. Some depicted coffins with stenciled signs in French that say “A French soldier in Ukraine.” Others include a sign that says in Ukrainian “Return the elections back to Ukrainians.”

It was the latest of several strange incidents in recent months worrying French authorities as Paris prepares to host the Olympic Games in 50 days.

Three people were detained and released Monday after they allegedly placed five coffins at the foot of the Eiffel Tower, a Paris landmark that will feature prominently in the upcoming games.

Last month, graffiti showing red hands appeared on the Holocaust Memorial in Paris.

And in October, soon after the start of the Israel-Hamas war, stencils of blue Stars of David appeared on Paris buildings. French authorities accused Russian security services of stirring up controversy around the stars.

French Foreign Minister Stephane Sejourne said both incidents involved people paid to destabilize and drive wedges in French society.

The Russian Embassy in Paris denied any Russian involvement.