PHOTO: People carry a an injured person at the Route 91 Harvest country music festival PHOTO CREDIT: ABC NEWS

President Donald Trump has ordered that flags flown at half-mast across the U.S. in honour of the victims of the Las Vegas shooting, which led to the killing of at least 50 people and injuring more than 400 others.

Trump, in a proclamation he signed immediately after his address to the nation on the incident, declared that the country was heartbroken.

“Our nation is heartbroken. We mourn with all whose loved ones were murdered and injured in last night’s horrible tragedy in Las Vegas, Nevada. As we grieve, we pray that God may provide comfort and relief to all those suffering.

“As a mark of respect for the victims of the senseless act of violence perpetrated on October 1, 2017, by the authority vested in me as President of the United States by the Constitution and the laws of the United States of America I hereby order that the flag of the United States shall be flown at half-staff at the White House and upon all public buildings and grounds, at all military posts and naval stations.

He said the action would also affect all naval vessels of the Federal Government in the District of Columbia and throughout the United States and its Territories and possessions until sunset, October 6, 2017.

“I also direct that the flag shall be flown at half-staff for the same length of time at all United States embassies, legations, consular offices, and other facilities abroad, including all military facilities and naval vessels and stations.”

On Sunday night, a gunman opened fire from a hotel room above a packed, outdoor concert in Las Vegas in the deadliest mass shooting in modern U.S. history.

Clark County Sheriff Joe Lombardo said the shooter, identified as Stephen Paddock, 64, was found dead by officers who stormed his 32nd-floor room at the Mandalay Bay Resort and Casinos.

Trump, in his address on the tragedy, praised first responders, including the Las Vegas Metropolitan Police Department, “for their courageous efforts”.

“In moments of tragedy and horror, America comes together as one – and it always has. We call upon the bonds that unite us – our faith, our family, and our shared values. We call upon the bonds of citizenship, the ties of community, and the comfort of our common humanity.

“Our unity cannot be shattered by evil. Our bonds cannot be broken by violence. And though we feel such great anger at the senseless murder of our fellow citizens, it is our love that defines us today — and always will, forever.”

He said the speed with which they reacted to the shooting was “miraculous and prevented further loss of life”, noting that the FBI and Department of Homeland Security are working with local authorities on the investigation.

“Hundreds of our fellow citizens are now mourning the sudden loss of a loved one – a parent, a child, a brother or sister. We cannot fathom their pain.

“We cannot imagine their loss. To the families of the victims: We are praying for you and we are here for you, and we ask God to help see you through this very dark period.”

The president quoted from Scripture that “the Lord is close to the brokenhearted,” and said he and first lady Melania Trump were praying for the speedy recovery of the wounded and for the families of the victims.

Trump announced that he would be visiting Las Vegas on Wednesday to sympathise with the victims and share in the griefs of the people of the city. NAN