U.S. media reported an hour before the shooting at a Wisconsin resort, with some reporting that at least two people were killed and five others were injured.
A Wisconsin television network quoted informed sources as saying that a gunman who shot dead one person and injured five others at a Green Bay resort had been shot dead by police.
However, other sources reported that the man is in custody.
Police declined to give details of the incident, the identity of the shooter and his motive, and did not comment on the condition of the injured in the night shooting.
Some media outlets also reported that eight people were injured in the shooting.
The shooting in Wisconsin is the latest in a series of violent armed incidents in recent weeks in the United States.
On April 3, a deadly shooting occurred at a store in Boulder, Colorado, killing 10 people, including a police officer.
On April 7, two people were killed and eight others were injured in a shooting off the coast of the eastern US state of Virginia.
On April 12, it was announced that a shooting at a commercial location in Orange County, California, resulted in the death of four people and the injury of two others.
According to IRNA, the US-controlled US House of Representatives has passed two bills on arms control in the United States to reduce the wave of armed crime.
The first bill increases the records of arms buyers. Under the second decree, the relevant authorities will be required to review the records of arms buyers within 10 working days and then issue a sales license.