OMAHA, Neb. (AP) — A federal judge has refused to dismiss a lawsuit challenging Nebraska’s attempt to regulate tobacco sales by two Winnebago Tribe subsidiaries.

HCI Distribution and Rock River Manufacturing said in their April lawsuit that tribal commercial activities are protected under federal law and that Nebraska has no regulatory authority over the tribe’s cigarette operations.

The Sioux City Journal reports that U.S. District Judge John Gerrard said in his ruling Wednesday that more evidence will be needed to settle issues raised in the case, so he is letting the case proceed. The state had sought the dismissal.

The Nebraska Department of Revenue issued tax assessments against several reservation-based cigarette retailers in 2014, saying they made sales subject to state cigarette tax laws.