A Bronx mother says her 4-year-old son claims his Bronx teacher hit him on the head with a ruler for being noisy in class.

Tanairis Martinez says her son came home from school with a bruise on his forehead on Jan. 14.

"When he told me, my stomach just sank and I was in tears ... even up until today," said Martinez.

Martinez says since that day her son Liam has been getting nose bleeds.

"She's a very sweet woman, I trusted her I never saw any signs, but kids don't lie at 4 years old," said Martinez.

She says she has kept her son out of school since the incident and is looking for a new school.

A Department of Education spokesperson says the teacher has been reassigned away from the classroom, while the allegations are being investigated. The NYPD says the Bronx Child Abuse Squad is also investigating the case.