PRESTON, Minn. (AP) _ A judge ruled Monday that Amish people must display slow-moving vehicle signs on their horse-drawn buggies, but lawyers said the religious-freed om issue could go all the way to the U.S. Supreme Court.

State law requiring the signs does not violate the Amish's First Amendment right to freedom of religion, Fillmore County District Judge Clement Snyder said in his ruling.

Phillip Villaume, an attorney representing the Amish, said the case will be appealed to the state Court of Appeals.

Villaume and Fillmore County Assistant Attorney Matt Opat said the case likely will go to the Minnesota Supreme Court and may end up in the U.S. Supreme Court.

Fifteen Amish people appeared before Snyder in October after they had been ticketed for violating the state regulations. They were cited for failing to obey a Minnesota law requiring them to display triangular slow-moving vehicle signs on the rear of their buggies. During the day, the signs can be black with white reflective tape. When it is dark or foggy, the signs must be orange.

Opat argued that prosecuting the Amish for not complying with the state law was a case of public safety, not religious prosecution. He said public safety issues significantly outweigh any infringement the law may have on the Amish's constitutional right of religious freedom.

Villaume, of St. Paul, said it was ironic that the Amish, who settled in the United States in the 1700s to avoid religious persecution, were still fighting battles to protect their religion.

A witness for the Amish said they oppose displaying the signs because they feel the signs are ''worldly'' representations of man, not God, and they hope to keep their religious practices separate from the modern world.

But Opat said the Amish willingly displayed the signs for years, but then quit displaying them within the past year or two. There also has been no uniformity among the Amish in Fillmore County, he said, noting that some display the orange signs, some the black and white signs and others no signs at all.

The Amish have regularly used the color red on their barns, leading the prosecutor to question whether the dispute was really over religious beliefs. As a result, he said in October, the Amish have a ''pick-and-choose society.''