Two people slipped into eastern North Dakota from Canada, abandoned three backpacks jammed with dozens of guns and fled back over the border without capture, federal officials said Wednesday.

A report of suspicious activity led U.S. Border Patrol agents and their dog assigned to the Grand Forks, N.D., sector's Pembina station made the discovery in the early hours of May 15 near Neche, just south of Canada and about 16 miles west of North Dakota's border with Minnesota.

The agents arrived to the location and saw two people fleeing, said Steven Bansbach, spokesman for U.S. Customs and Border Protection. With the help of their dog, Odin, the agents found the backpacks, which held 65 handguns, 65 pistol magazines, two rifles, a silencer and two rifle magazines.

"The two people absconded back to Canada before we were able to get a description," Bansbach said.

"Bulk firearms seizures are an uncommon occurrence for the Grand Forks sector," chief patrol agent Scott D. Garrett said in a statement, adding that his agents' quick response "led to the successful outcome of this incident."