A knife-wielding man stabbed a 10-month-old baby in her stroller, critically injuring her, police said.

Isabelle Avins (search) was rushed to a hospital where she underwent surgery Wednesday night. She was listed in critical but stable condition, police spokesman Detective Brian Sessa (search) said.

At the family's request, the hospital on Thursday declined to provide further details.

The nanny was walking with the baby around 5 p.m. when the man approached them a short distance from the girl's home, Sessa said.

"He just came out of nowhere," witness Hennessy Arias told the New York Post in Thursday's editions. "The baby was hysterical, crying. ... She was crying and trying to gag for air."

The nanny, identified only as a 20-year-old woman, screamed for help and cradled the baby.

Isabelle's father, Jon Avins (search), also praised the nanny.

"The babysitter saved her life," he told reporters outside the family's apartment building. "She's like a member of our family."

Bernard Derr, 48, a man with a history of psychiatric problems, was taken into custody a short time after the attack and held on attempted murder and other charges, police said.