Updated 7.50pm 

A SEMINUDE GUNMAN shot six people, killing four, early this morning at a restaurant on the outskirts of Nashville in Tennessee, police have said.

Three people died at the scene, while a fourth person died in hospital. Two injured people are being treated in hospital.

Having twice identifying the shooter as “nude,” police later tweeted that the gunman had shed his coat and was last seen wearing black pants but no shirt.

The Metropolitan Nashville Police Department said in a statement that the shooting occurred at a Waffle House restaurant in Antioch, a suburb southeast of Nashville, at 3.25am (9.25am Irish time).

The restaurantSource: Metro Nashville PD/Twitter

Police said that "murder warrants are now being drafted against Travis Reinking," a 29-year-old from Morton, Illinois who was earlier identified as a person of interest.

Local police spokesman Don Aaron told a televised news briefing that Reinking had arrived in a pickup truck, and opened fire on people gathered outside the restaurant.

He then went inside the restaurant where more shots were fired, and a patron was hit, before someone was able to grab his rifle from him, Aaron said.

"This is a very sad day for the Waffle House family. We ask for everyone to keep the victims and their families in their thoughts and prayers," Waffle House wrote on Twitter.

Gun control 

Police posted a photo of an AR-15-style assault rifle, saying it was the weapon used in the shooting.

AR-15s have been repeatedly used by mass shooters in the US, where the debate over gun control is fierce and gun violence is frequent.

The rifle used by the shooterSource: Metro Nashville PD/Twitter

AR-15 rifles were used to kill 58 people in Las Vegas last October, while Florida school shooter Nikolas Cruz in February opened fire on his former high school with an AR-15 style rifle, killing 17 students and staff members.

In the wake of the Florida massacre, student survivors launched a gun control campaign -- drawing hundreds of thousands to demonstrations -- and businesses including Walmart and Dick's Sporting Goods took measures to restrict access to assault weapons and firearms in general.

However, Congress is sitting on its hands when it comes to the issue.

Meanwhile, an ABC News/Washington Post poll published on Friday suggested that support for a ban on assault weapons has risen sharply in the past few months.

Some 62% of those polled said they support a nationwide ban on the sale of assault weapons, up from 50% in mid-February and 45% in late 2015.

- © AFP 2018, with reporting by Órla Ryan