A bench warrant was issued Thursday for antiwar activist Cindy Sheehan, who did not appear for arraignment Thursday in a Washington, D.C., courtroom to face charges related to her Sept. 10 disorderly conduct arrest on Capitol Hill.

District of Columbia Superior Court Judge Michael McCarthy issued the order to Sheehan around noon, a court spokeswoman said. The warrant says she is to be arrested and brought before the court. She also faces one count of unlawful assembly.

"She wasn't aware that there was a court appearance today," said Sheehan's spokeswoman, Tiffany Burns, reached by cell phone.

"We'll have the attorney deal with this immediately, so as soon as she's rescheduled to appear, she'll be there," Burns added.

Burns said Sheehan was at home in California Thursday, and did not receive the paperwork notifying her of the court date.

However, a court document obtained by FOXNews.com dated Sept. 10, signed by Sheehan, advised her to appear Thursday at 8:30 a.m. The warrant issued Thursday sets a $50 bond for her arrest.

Sheehan's Sept. 10 arrest — one of several in recent years — came as a tense hearing on the Iraq war underway at the Cannon House Office Building. Gen. David Petraeus and U.S. Ambassador to Iraq Ryan Crocker were were giving their highly anticipated report on military and political progress in Iraq to the House Armed Services Committee.

Sheehan was among dozens of protesters at the hearing with the antiwar group Code Pink, at least eight of whom were arrested. Sheehan was arrested alongside her sister, Dee Dee Miller, and both were charged with disorderly conduct.

Desiree Fairooz, a Code Pink member, also was arrested Sept. 10, and was surprised to learn that a warrant had been issued for Sheehan. She was reached by phone at a Washington, D.C., Code Pink gathering place.

"It was probably just an oversight," said Fairooz, a children's librarian.

Fairooz said she and Sheehan rode together in the police van after they were arrested, and she knows of no talk since among her fellow protesters of trying to evade the court system.

"That would be a total waste of time. Our energies are spent working on Capitol Hill trying to involve our congressmen and women and senators ... Spending more time in jail is counterproductive," Fairooz said.

Fairooz also discounted the notion that getting arrested was a notch in a protester's belt — although she said she had been arrested three times, all three for antiwar protests. For her most recent conviction, she served two days in jail of a five-day term "for good behavior."

"I definitely hope to avoid it. We'd rather have our voices heard without having to spend time in a 4-by-12 cell," Fairooz said.

Fairooz said she had not spoken with Sheehan since the arrest, but after her own arraignment, her court date was set for Dec. 26. She said her attorney has warned her that she could be facing more jail time.

"They seem to be cracking down on us repeat offenders," Fairooz said.

Sheehan also recently announced she will run against House Speaker Nancy Pelosi in next year's election because she believes Pelosi has not done enough to stop the war in Iraq.

Sheehan became a household name in 2005 when she and hundreds of protesters camped outside President Bush's Crawford, Texas, ranch. The camp came to be known as Camp Casey, named after Sheehan's son, Casey, who died in combat in 2004.