One person has been killed when federal authorities arrested the leader of an armed occupation at a wildlife refuge in the US state of Oregon during a traffic stop, law enforcement sources say.

Another person was injured, police said on Tuesday.

It was not immediately clear if other armed individuals remained occupying the remote Malheur National Wildlife Refuge in eastern Oregon or if Ammon Bundy’s arrest had ended the stand-off.

• Two dead after ute plunges off bridge
• Abetz may ‘vote down’ plebiscite
• Positive test for Zika in US

In a statement on Tuesday, the FBI said one individual “who was a subject of a federal probable cause arrest is deceased”. No other information about the deceased was immediately released.

The FBI said authorities arrested Bundy, 40, his brother Ryan Bundy, 43, Brian Cavalier, 44, Shawna Cox, 59, and Ryan Payne, 32, during a traffic stop on Tuesday afternoon on US Highway 395.

Authorities said another person, Joseph Donald O’Shaughnessy, 45, was arrested in Burns.

About 40km of Highway 395 in northeast Oregon was shut down in both directions, a spokesman for the state department of transportation said.

Local media reported that a hospital in nearby Burns had been placed on lockdown.

Bundy’s group, which has included people from as far away as Arizona and Michigan, seized the headquarters of the Malheur National Wildlife Refuge on January 2 as part of a long-running dispute over public lands in the West.

Bundy is the son of Nevada rancher Cliven Bundy, who was involved in a high-profile 2014 standoff with the government over grazing rights.

The takeover at Malheur was the latest flare-up in the so-called Sagebrush Rebellion, a decades-old conflict over the US government’s control of millions acres of land in the West.

The occupiers said their move was in support of two local ranchers who were returned to prison this month for setting fires that spread to federal land. The ranchers’ lawyer has said the occupiers do not speak for the family.

Law enforcement officials had largely kept their distance from the buildings at the refuge, 48km south of the small town of Burns in rural southeast Oregon’s Harney County, in the hope of avoiding a violent confrontation.