Pope Francis joined other church leaders in the USA and around the world to offer prayers and condolences after at least 50 people were killed and more than 400 wounded in Las Vegas in the worst mass shooting in American history.
The pontiff's message praised emergency services involved and commiserated with those affected by 'this senseless tragedy'.
Officials identified 64-year-old Nevada resident Steven Paddock as the attacker and said he shot himself before police entered the hotel room on the 32nd floor of the Mandalay Bay hotel where he fired from. His motive is not yet known and officials initally held back from describing the incident has 'domestic terrorism'.
Videos posted on social media show automatic gunfire spraying 22,000 people gathered for a country music festival on the Las Vegas strip where artist Jason Aldean was playing.
Police said they found more than ten guns in Paddock's hotel room, where he had been staying since September 28.
Vatican Secretary of State Cardinal Pietro Parolin said the pope's message to Bishop Joseph Pepe of Las Vegas 'commends the efforts of those police and emergency services personnel, and offers the promise of his prayers for the injured and for all who have died, entrusting them to the merciful love of almighty God'.
The pontiff was joined by members of Donald Trump's evangelical advisory council including Paula White-Cain, his personal spiritual advisor, who described the attack as a 'horrific act of evil'.
She said: 'I am praying for every victim, family member, friend and the community of Las Vegas grieving from this horrific act of evil. May you feel the love of God and all of us standing with you in the midst of such pain and turmoil.'
She added: 'You have our strongest support, Las Vegas — every ounce of love and care we have is yours.'
Rev Samuel Rodriguez, president of the National Hispanic Christian Leadership Conference, anticipating the upcoming debate on US gun laws, said it is 'not a time for politics, but for prayer'.
He said: 'This is not a time for division, but for divine solicitation. We join our hearts, we all take our knees and we pray with all of our might for peace for the families of those whose lives have ended in this tragedy, and for all of those who are still fighting for their next breath.'
Robert Jeffress, senior pastor of First Baptist Dallas and another key advisor to Trump, echoed a similiar message as he said it was 'a day where there are no Democrats or Republicans'.
He said: 'Today is a day that will live long in American history as a day of tragedy, the largest mass shooting in America, ever. It is also a day where there are no Democrats or Republicans, there are no conservatives or liberals — we are all united as Americans.
'Together we cry out to God in their time of need. This is a time of great national need, and I call on pastors and religious leaders in every corner of the nation to call together their communities in prayer and compassion.'
Dr Ronnie Floyd, president of the National Day of Prayer, joined him and issued a nationwide call to pray for victims.
'The unthinkable and horrific acts of violence against innocent people in Las Vegas moves us to prayer immediately,' he said. 'May the peace of Jesus Christ be with those who have lost loved ones. We pray for those being cared for, as well as for all the first responders.'
Franklin Graham added he was praying for those affected.
Russell Moore, president of the Ethics and Religious Liberty Commission of the Southern Baptist Convention described the attack as 'horrifying'.