State and federal authorities urged a group of armed men occupying a U.S. wildlife refuge in Oregon to abandon the protest over land rights on Wednesday, a day after their leader and seven other people were arrested and one man killed.

Law enforcement tightened security around the Malheur National Wildlife Refuge after occupation leader Ammon Bundy and his group were taken into custody at a traffic stop on Highway 395 in northeast Oregon.

Authorities declined to give details of what led to the fatal shooting of one member of Bundy's group, identified by activists as Robert LaVoy Finicum, a rancher who acted as a spokesman for the occupiers. Bundy's brother, Ryan, was wounded in the incident.