COVENTRY, Vt. — A U.S. Border Patrol agent was fatally shot Monday on a highway in northern Vermont south of the Canadian border, authorities said.

The death was confirmed by the FBI and Benjamine Huffman, acting secretary of the Department of Homeland Security in Washington.

In a statement, the FBI said that in addition to the agent, a suspect in the shooting was killed and a second suspect was injured and taken into custody during the encounter on Interstate 91 in Coventry, about 20 miles from the Canadian border.

The FBI said there was no ongoing threat to the public.

Huffman said the death occurred “in the line of duty.” The identity of the agent, who was assigned to the U.S. Border Patrol’s Swanton Sector, was not immediately released. The sector encompasses Vermont and parts of New York and New Hampshire.

Federal authorities did not provide additional details but said they would be released as they became available.

A portion of Interstate 91 was closed in both directions for about two hours afterward. The northbound lane reopened just after 5 p.m. Besides federal authorities, the Vermont State Police was also investigating. The FBI responded from the Albany, New York, office.

Huffman said the death would be “swiftly investigated.”

“Every single day, our Border Patrol agents put themselves in harm’s way so that Americans and our homeland are safe and secure,” Huffman said in a statement.

Coventry is close to the U.S. Customs and Border Protection’s Newport Station, part of the Swanton Sector. The area includes 295 miles of international boundary with Canada.

In a joint statement, Vermont’s Sen. Bernie Sanders, Sen. Peter Welch and Rep. Becca Balint sent condolences to the agent’s family and said Border Patrol agents “deserve our full support in terms of staffing, pay and working conditions.”