PHOENIX (AP) — Gov. Jan Brewer has signed into law a bill to prohibit use or possession of medical marijuana at public universities, community colleges or child-care facilities.

Supporters included university officials and prosecutors, while the American Civil Liberties Union of Arizona and the Arizona Medical Marijuana Association opposed the bill's prohibition for higher education institutions.

A spokesman for the medical marijuana Association has predicted that the legislation will be challenged either by his group or somebody else on grounds that it violates a constitutional protection for voter-approved laws.