A man armed with a gun, hatchet and pepper-spray has attacked the people watching “Mad Max” at a movie theater in the US state of Tennessee, police say.

The incident happened at the Carmike Hickory 8 movie theater complex in Antioch, Tennessee, on Wednesday afternoon.

Antioch is a suburb of Nashville, about 24 kilometers (15 miles) southeast of the city.

The Metro Nashville Police Department reported shortly after 2:00 p.m. that the "suspect (is) dead."

Nashville Police spokesman Don Aaron told reporters that the suspect also had a hatchet.

The man was killed during a gunbattle with a SWAT team, Aaron said.

At least three people were injured when the suspect allegedly pepper-sprayed the crowd in the auditorium. One of the injured was also hit with the hatchet.

Aaron told reporters that the suspect was shot when he raised his weapon toward an officer and pulled the trigger. “That officer then fired on the suspect, and then backed away from the theater.”

"He was shot, fatally wounded, and has been pronounced deceased at the scene," he stated.

The suspect was wearing a surgical mask and a backpack which was strapped to the front of his body.

"The hazardous devices unit has examined the backpack that the suspect was wearing, they are not comfortable with what they are seeing. So in a short amount of time, that backpack will be detonated by the bomb squad," Aaron said.

"The mask may have been to try to negate the effects of the chemical spray he brought with him," the police spokesman said.