Arizona charter schools are suing the state Department of Education to try to block a planned reduction of money for teacher pay raises and other classroom costs.

The lawsuit filed Friday in Maricopa County Superior Court challenges the department's plans to withhold the money from funding over the next several fiscal years in order to offset overpayments in two previous fiscal years.

The Arizona Capitol Times reported the overpayments were made during an effort to make up for years when there was underfunding of a fund created under a voter-approved ballot measure.

The charter schools said nearly $6 million is at stake.

A department of education official said some district and charter schools were inadvertently given money that shouldn't have gone to them while others were underfunded.