JOLIET, Ill. (AP) — Police are searching for a man who caused thousands of dollars of damage in a Walmart in suburban Chicago by spraying disinfectant inside the store while wearing a surgical mask and a sign on his back declaring that he has the deadly coronavirus.

Two men apparently in their 20s walked into the store in Joliet on Sunday. One of them put on the yellow surgical mask and started spraying Lysol on clothing, produce and health and beauty items, causing nearly $10,000 in damage, police said.

“He was telling everyone the same thing, that he was protecting them from the virus,” Tony Prokes, a customer, told WLS-TV in Chicago. The man wore a homemade sign on his back that read, “Caution I have the Coronavirus.”

The apparent prank comes amid growing worldwide concern about the virus that has killed hundreds of people, most of them in mainland China, and sickened more than 20,000 around the world.

The U.S. has declared a public health emergency and took drastic steps to restrict entry into the country. In Chicago, health officials in Chicago reported recently that a woman who had traveled to Wuhan, China, had become infected with the virus. Later they reported that the woman had infected her husband in what the Centers for Disease Control and Prevention said was the first person-to-person spread of coronavirus in the United States.