The woman who started an anti-war demonstration near President Bush's ranch nearly two weeks ago left the camp Thursday after learning her mother had had a stroke, but she told supporters the protest would go on.

Cindy Sheehan (search) told reporters she had just received the phone call and was leaving immediately to be with her 74-year-old mother at a Los Angeles hospital.

"I'll be back as soon as possible if it's possible," she said. After hugging some of her supporters, Sheehan and her sister, Deedee Miller, got in a van and left for the Waco airport about 20 miles away.

Sheehan, whose 24-year-old son Casey died in Iraq, said the makeshift campsite off the road leading to Bush's ranch would continue.

The camp has grown to more than 100 people, including many relatives of soldiers killed in Iraq. After Sheehan left, dozens of the demonstrators gathered under a canopy to pray for her mother.

Sheehan, of Vacaville, Calif., had vowed to remain at the camp until Bush met with her or until his monthlong vacation ended.

Her protest inspired candlelight vigils across the country Wednesday night, and she has drawn sympathy for the loss of her son, which says tore apart her marriage as well.

Bush has also said he sympathizes with Sheehan. White House spokeswoman Dana Perino said earlier Thursday that the president said Sheehan had a right to protest but that he did not plan to change his schedule and meet with her. Bush is scheduled to return to Washington on Sept. 3.

Two top Bush administration officials talked to Sheehan the day she started her camp, and she and other families met with Bush shortly after her son's death and before she became a vocal opponent of the war.

Michelle Mulkey, a spokeswoman for Sheehan, said Sheehan hoped to be back in Texas in a day or two, depending on her mother's condition.

Sheehan and the other demonstrators have camped in ditches along the road to Bush's ranch since Aug. 6. After complaints from some neighbors, they planned to start moving the camp site Thursday and Friday to a private one-acre lot owned by Fred Mattlage, who opposes the war and offered his property to give them more room and safety.

Thursday afternoon, FBI whistleblower Coleen Rowley (search) and Sen. Becky Lourey (search), a Minnesota lawmaker whose son died in Iraq, joined them and planned to stay for a few days.

The two walked with about 150 protesters two miles down the road to the checkpoint outside Bush's ranch with letters urging first lady Laura Bush to try to get her husband to meet with Sheehan.

Rowley said going to war was a mistake because the link between Iraq and Al Qaeda was exaggerated.

"We have got to call America's attention to this in order to stop the continuation of errors," Rowley said. She is now retired from the FBI but gained national attention after criticizing the agency for ignoring her pleas before the Sept. 11 attacks to investigate terrorism suspect Zacarias Moussaoui more aggressively.

Sheehan also has opponents. A conservative California-based group, Move America Forward, has produced a national television commercial to say Sheehan doesn't speak for military families. Group founder Deborah Johns, whose son is a Marine, is featured in the ad.

"I'm here to tell you that military families support our troops AND their mission — in spite of what people like Cindy Sheehan say," Johns says in the ad. "Cindy Sheehan certainly doesn't speak for me, our military families or our men and women serving in Iraq and Afghanistan."

Johns said she believes Sheehan's crusade discredits the soldiers serving in Iraq.