An advocacy group says it has uncovered evidence of abuse and neglect at a Massachusetts public kindergarten that serves many children with disabilities.

The Boston-based Disability Law Center said Thursday that among other things, the Crowell Kindergarten Center in Haverhill overused restraints on at least one 5-year old student with disabilities and punished students for crying or acting up by keeping them in closets.

The Center said the school violated state and federal laws. It said it started investigating after receiving complaints about student treatment.

Crowell has about 150 students.

Haverhill Superintendent James Scully said in a statement that the district is reviewing the Center's report, and several issues have already been addressed since the allegations surfaced last year.

Scully did not say whether any staff was disciplined.