Donald Trump has addressed his first indoor campaign rally since June, in defiance of coronavirus guidelines.
The US President spoke to large crowds at the event outside Las Vegas on Sunday - despite a ban on gatherings of more than 50 people in Nevada.
People were pictures sitting crowded together, with many failing to wear masks and to social distance from eachother.
Nevada's Democrat Governor Steve Sisolak condemned the President for flouting state rules, accusing him of "reckless and selfish actions that are putting countless lives in danger here".
"The President appears to have forgotten that this country is still in the middle of a global pandemic," he tweeted.
The event was the first indoor rally the President has held since June, when an event in Tulsa, Oklahoma, was later blamed for a coronavirus spike in the local area.
Mr Trump's Democrat rival Joe Biden has criticised him for hosting campaign events during the pandemic, which has killed more than 194,000 people in the United States.
But the President had blasted Mr Biden for doing fewer events ahead of the November 3 election.
Ahead of the rally, Mr Trump sent a series of bizarre tweets: "Once again, Sleepy Joe told the press they could go home at 9 A.M.
"Meanwhile, your Favorite President, me, will go to Reno, Nevada tonight, three stops in Las Vegas tomorrow, with California and Arizona on schedule Monday.
"Don’t worry, we won’t be taking off Tuesday, either!"
He added: "While I travel the Country, Joe sleeps in his basement, telling the Fake News Media to “get lost”."
The President's campaign said the Nevada rally was opportunity for supporters to exercise their rights to peaceful assembly.
"If you can join tens of thousands of people protesting in the streets, gamble in a casino, or burn down small businesses in riots, you can gather peacefully under the First Amendment to hear from the president of the United States," spokesman Tim Murtaugh said.
Participants were to have temperatures taken before entry and be given a mask they would be encouraged to wear, the campaign said.
