A Greenburgh nanny was arrested for allegedly assaulting an 18-month-old boy in her charge.

According to police, 23-year-old Bronx resident and apparent illegal alien Bibi Safeena Zaman admitted to violently shaking the baby while he and his 3-month-old sister were in her care.

However, police say Zaman originally told them the baby fell down the stairs when she called 911 Thursday afternoon. Doctors at Westchester Medical Center told police that the baby?s retinas were detached and he suffered bleeding on the brain, which they say is consistent with shaken baby syndrome.

Zaman later admitted to police that she lied and in fact shook the baby boy after apparently becoming angry when he wouldn't eat.

Zaman is being held without bail at Westchester County Jail. A bail hearing is scheduled for Friday if Zaman?s attorney can prove her visa has been renewed.

Meanwhile, the baby boy remains in pediatric intensive care.