Republican presidential candidate Donald Trump posted a tweet Sunday claiming the City of Phoenix violated its fire code by allowing a crowd at his event Saturday that was more than three times the room's capacity.

Trump and his campaign were declaring through the day Saturday that there were 10,000, 15,000 or 20,000 people at the event at the Phoenix Convention Center. The hall where the rally was held has a maximum occupancy of 4,200.

In the tweet Sunday, the Trump campaign said Phoenix officials "don't want to admit that they broke the fire code by allowing 12-15,000 people in the room."

A follow-up tweet Sunday from the Trump account said "Convention Center officials did not want to have thousands of people standing outside in the heat, so they let them in."

A spokeswoman for the Phoenix Fire Department and a person who was on-site Saturday and familiar with security arrangements said Trump was wrong.

"There's no way that would be allowed," said Phoenix Fire Department spokeswoman Shelly Jamison.

"Once capacity was reached, we closed the doors. No rules or codes were broken and no one was in danger at anytime."

Jamison said the Trump campaign had been offered a larger room at the convention center but declined.

The person familiar with the security arrangements, who asked not to be identified, said the convention center, which has its own fire marshal, was very strict on safety.

"It wouldn't have been allowed," the person said of Trump's larger crowd numbers. "The convention center let the client know that 4,200 is where we're going to max out."

A Trump representative at Saturday's event told reporters that there were 4,200 to 4,500 people inside the packed hall. The security official said a clicker at the door showed 4,299 was the final number of people allowed inside.

Trump bragged during his speech Saturday that his crowd was larger than a recent crowd for Democratic presidential candidate Sen. Bernie Sanders of Vermont. Sanders drew an estimated 9,600 supporters to a Wisconsin event two weeks ago.

Trump campaign representatives did not respond to calls or emails Sunday seeking more information about their claims.

Trump's convention center event came together at the last minute. The original site, the Arizona Biltmore resort, wasn't able to accommodate the anticipated crowd after there was surge of ticket requests.

Trump said the Biltmore room would have held 500 people. Late Thursday, the campaign moved the event to the North Hall at the convention center. The event was "sold out," reporters were told, with up to 5,000 requests online for the free tickets. An online wait list was set up.

Yet the campaign put out emails late Friday and early Saturday making more tickets available. It's not unusual for political event organizers to invite more people than a room might hold. The thinking is that some of the people claiming tickets won't show up.

But the Trump campaign distributed 15,000 tickets, according to CNN. Trump posted a photo of the full convention center hall Saturday night with the line, "This is what 15,000 people looks like."