U.S. Capitol Police said it is working with a number of congressional offices after an off-site mail screening facility intercepted a package addressed to Rep. Maxine Waters, D-Calif.

“The USCP also is working closely with the House and Senate Sergeant at Arms, the House Chief Administrative Officer, and Congressional leaders to ensure the safety and security of Members of Congress, their staffs, and their offices,” a press release from USCP said.

The House and Senate sergeants-at-arms are the highest-ranking federal law enforcement officers in the two chambers of Congress.

Capitol Police are also working with local law enforcement in the areas were suspicious packages were found including Florida and California, as well as a screening facility in Maryland.

The congressional mail screening facility in Capitol Heights, Md., intercepted a suspicious package addressed to Waters.

Suspicious packages were also found outside of offices for Democrats Rep. Debbie Wasserman Schultz in Florida and Sen. Kamala Harris in California on Wednesday.

Suspicious packages were sent to other Democratic figures this week, including former President Barack Obama, former Secretary of State Hillary Clinton, liberal billionaire donor George Soros, and former Attorney General Eric Holder.