An anti-vaccination protester doused California lawmakers with a red liquid Friday, which prompted authorities in Sacramento to shut down the Senate session to investigate.

State Sen. Scott Wiener, D-San Francisco, said on Twitter that the substance was dropped from "the elevated public gallery" at the Capitol shortly before 5:30 p.m. "The person who committed this assault screamed it was baby blood," he said.

The California Highway Patrol, which police the Capitol, said that Rebecca Dalelio, 43, was arrested on suspicion of assault, vandalism, disorderly conduct at the Capitol and other allegations.

"During the Senate Session inside the California State Capitol, a demonstrator in the Senate Gallery stood up and threw a feminine hygiene device containing what appeared to be blood, onto the Senate floor," the CHP said "The liquid landed on several members of the Senate. The female proceeded to walk out of the Senate Gallery and into the hallway where she was arrested."

Wiener said the suspect was part of an anti-vaccine group of protesters upset over new laws that place tighter controls on doctors who issue vaccination exemptions to schoolchildren as well as schools with relatively high numbers of unvaccinated children.

"These anti-vaxxers are engaging in criminal behavior," Wiener tweeted. "They’ve now repeatedly assaulted Senators & are engaging in harassing & intimidating behavior every single day, as we try to do the people’s work."

Sen. Steve Glazer, D-Orinda, said in a tweet no longer available that he was struck by the red liquid alongside Sen. Melissa Hurtado, D-Sanger; Sen. Cathleen Galgiani, D-Stockton; Sen. Nancy Skinner, D-Berkeley; Sen. Holly Mitchell, D-Los Angeles and Sen. Susan Rubio, D-Baldwin Park.

A spokeswoman for Sen. Pro Tem Toni G. Atkins, D-San Diego, said the session resumed after 8 p.m. Friday was the final day of the legislative session.

"California’s legislative process, as well as our doors, should remain open to all who wish to observe or speak out on a variety of issues, but we cannot allow anyone to endanger others," Atkins said in a statement. "The behavior that occurred in the Senate Chamber is unacceptable and has been dealt with by Capitol law enforcement. We will continue to do the people’s important business."