The person who stole Homeland Security Secretary Kristi Noem’s handbag containing $3,000 in cash over the weekend was wearing a medical mask and snatched the bag from underneath her chair, officials said.

“She could feel this person as they snatched her bag, but thought they were her grandchildren playing until realizing a minute later that her bag was gone,” said Tricia McLaughlin, a spokeswoman for the Department of Homeland Security. “Her bag was under her feet and the perpetrator hooked the bag with his foot and dragged it across the floor and put a coat over it and took it.”

The robbery happened on Sunday night at a restaurant in Washington where Ms. Noem was having dinner with her family. The handbag also held Ms. Noem’s driver’s license, medication, apartment keys and blank checks.

Ms. Noem runs a department that is in charge of the nation’s security, including border control and immigration and terrorism protection.