Press TV- At least 50 people have been killed and over 200 others injured when a gunman opened fire at a music concert in Las Vegas, Nevada, making it the deadliest mass shooting in modern US history.

The "nonstop gunfire" sent bystanders outside the resort scrambling for their lives while tourists hid in their hotel rooms. Disturbing footage�showed the aftermath as the injured lay on stretchers or on the ground with responders and bystanders trying to provide assistance.

Las Vegas Metro Police Sheriff Joseph Lombardo told reporters on Monday morning that "this is an ongoing investigation, but we are comfortable that the primary aggressor in this event is -- has expired or passed away, and is no longer a threat."

Las Vegas Police Department advised people in a statement on Sunday night to stay away from Mandalay Bay Casino on the south end of the Vegas strip on Las Vegas Boulevard and across from McCarran International Airport.

"Confirming that one suspect is down. This is an active investigation. Again, please do not head down to the Strip at this time," LVMPD said in a tweet.

Thousands of fans were attending the concert next to the Mandalay Bay which was part of a three-day music festival.�Witnesses said�they thought�fireworks were going off as part of the concert.

Gunman and his companion identified


[caption id="" align="alignnone" width="555"] Stephen Paddock has been identified as the gunman.[/caption]
The suspected gunman, has been identified as 64-year-old Stephen Paddock from Mesquite, Nevada. He had reportedly checked in as a hotel guest.

He was on the 32nd floor of the Mandalay Bay Resort and Casino, the police chief said.

"Officers responded to that location and engaged the suspect at that location,"�Lombardo said, adding the suspect was dead.

Special SWAT units were deployed to the scene of the shooting. Police shut down the strip


[caption id="" align="alignnone" width="555"] Mari Lou Danley[/caption]
Police released the name of a female companion of the gunman, identified as Mari Lou Danley, 62.

According to authorities, Danley who was being sought as�a person of interest has been located.


[caption id="" align="alignnone" width="555"] Las Vegas police stand guard along the streets outside the festival grounds of the Route 91 Harvest on October 1, 2017 in Las Vegas, Nevada. (Photo by AFP)[/caption]
Witnesses said the gunman opened fire with an initial burst and then appeared to reload as he continued his firing spree.

Police also asked onlookers to avoid sharing "tactical positions" of its officers on the internet out of fear that it would endanger the operation.


[caption id="" align="alignnone" width="555"] A person lies on the ground at the Route 91 Harvest country music festival after apparent gun fire was heard in Las Vegas, Nevada, October 1, 2017. (Photo by AFP)[/caption]
Singer Jason Aldean was on stage when the shooting started. And it came towards the end of the concert.

"I guess it was an automatic weapon going off but it literally sounded like firecrackers. Then soon enough there was commotion on the Mandalay Bay side of the stage. They were motioning for medics to come and safety people to come and Jason Aldean ran off the stage," he said.

"Everybody in the vicinity went down. I don't know if they were ducking or if they were but it was chaos."


[caption id="" align="alignnone" width="555"] People carry a person at the Route 91 Harvest country music festival after apparent gun fire was heard in Las Vegas, Nevada, October 1, 2017. (Photo by AFP)[/caption]
White House Press Secretary Sarah Sanders said in a statement Monday morning that President Donald Trump had been briefed on the mass shooting.

"We are monitoring the situation closely and offer our full support to state and local officials," Sanders said. "All of those affected are in our thoughts and prayers."

Shortly after Sanders� statement, Trump tweeted, "My warmest condolences and sympathies to the victims and families of the terrible Las Vegas shooting. God bless you!"


My warmest condolences and sympathies to the victims and families of the terrible Las Vegas shooting. God bless you!


� Donald J. Trump (@realDonaldTrump) October 2, 2017

Nevada politicians also responded to the massacre, denouncing the violence and offering thanks to first responders.

"Senseless, horrifying act of violence in Las Vegas tonight," Republican Senator Dean Heller said in a tweet. "Thankful for police and first-responders on the scene," Heller said.

Nevada Governor Brian Sandoval, a Republican, called the shooting a �tragic� and �heinous act of violence" and offered his prayers for the victims.