Conservationists studying bats in Arizona were recently confronted by a group of armed militia members who confused them for border crossers or smugglers, a local sheriff told television station KOLD.

The TV station reported on Tuesday that Santa Cruz County Sheriff Tony Estrada said the militia members were wearing camouflage and were heavily armed when they arrived on ATVs and confronted the scientists on the night of Aug. 23.

“Obviously they mistook them for smugglers or illegal entrants,” said Estrada. “They were armed. They put a spotlight on them.”

The scientists reported the incident to the Santa Cruz County Sheriff’s office and were unreceptive to the militia’s apology. Estrada said the confrontation luckily didn’t turn violent but noted that the volunteer militia isn’t welcome in Santa Cruz County.

“They really don’t accomplish anything,” Estrada said. “They really don’t. With about a 1,000 border patrol agents here in Santa Cruz County, a little group of militia men are not gonna make any difference at all. As a matter of fact, they’re going to get in the way and they could get hurt. Or they could hurt somebody else.”