OMAHA, Neb. (AP) — Authorities are investigating vandalism at the Nebraska U.S. senators' offices in Lincoln and Omaha.

Police say someone tossed a reddish-brown liquid Tuesday night or Wednesday morning on the doorway of Sen. Deb Fischer's Omaha office. Someone also placed stickers touting protest group Betsy Riot. The protest group has described itself as a "decentralized neo-suffragette, punk-patriot resistance movement."

Lincoln police say what officers described as "fake blood syrup" was splattered Tuesday night or Wednesday morning on doors and windows at Sen. Ben Sasse's Lincoln office. A Betsy Riot sticker was placed there as well.

The two Republicans voted Tuesday to begin debate on repealing sections of the Obama administration's Affordable Care Act. It's unclear whether the vandalism was done in protest.

No arrests have been reported.