A 48-year-old woman who allegedly stabbed at least five people, and threatened a 3-year-old girl, on an Oakland-bound Greyhound bus was in surgery Monday in Visalia, authorities said.

Around 7:15 a.m., the bus left Las Vegas and made its fifth stop of the day on F Street in Bakersfield, Tulare County Sheriff Mike Boudreaux said at an evening press conference.

When the woman boarded, she appeared to be delusional and drew attention from passengers and the driver, who ordered her off the bus and conversed with her before allowing her back on, Boudreaux said.

About 45 minutes north of Tulare on Highway 99, the woman stood up from her seat near the front of the bus and walked toward the back.

When the woman then produced a knife, grabbed the 3-year-old girl by the neck and held her at knifepoint, the girl’s mother jumped up and began to fight her. The woman knifed the mother in the abdomen, Boudreaux said.

As the bus driver stopped the bus and charged back toward the woman, two Good Samaritans — identified as Nathan Wanhala, 30, and Spencer Williams, 27 — jumped on the woman to stop her. In doing so, both men suffered injuries, with Wanhala suffering a significant laceration to one hand and Williams sustaining minor injuries to knuckles on one hand.

The woman managed to try to turn the knife on herself, suffering wounds to her neck and chest, but the two men eventually were able to wrest the knife away from her and toss it toward the rear of the bus.

Firefighters, paramedics and California Highway Patrol officers responded to the bus after a 911 call, and got all 13 passengers off safely while treating victims and taking them to Kaweah Delta Medical Center in Visalia.

Wanhala, who spoke at a press conference Monday evening, said he was on his way back to Santa Cruz after visiting his father in Kingman, Arizona. He was sitting behind the mother and daughter when it all happened at once.

“The woman got up and forced her way between, and cussed at them. She said if she said anything she’d kill her daughter,” Wanhala said. “The lady showed a knife and started to get hysterical. She started stabbing at the mother and that’s when I jumped up and tried to grab the knife and got stabbed myself.”

Wanhala was modest about his actions and praised all who helped.

“I’m glad everybody was there and the bus driver did what he did to stop her, that we were there and we could help,” he said.

Contact George Kelly at 408-859-5180.