A U.S. border agent in Vermont shot at three suspects and nabbed two, but a third escaped after an encounter near the Canadian border at Derby Line, authorities said.

The officer was interviewing two men and woman in the vicinity of Baxter Rd. in Derby Line. early Monday morning when the agent was assaulted, U.S. Border Patrol operations officer Mark Henry told CBC.ca.

The officer fired two shots with his weapon, Henry said.

One of the men is believed to have fled north into Canada, while the other man and woman were taken into custody. They were not armed.

It's not clear whether the missing suspect was armed or wounded by the shots, the agency said.

The U.S. Border Patrol would not confirm the suspects' nationalities.