In her first rally since becoming the presumptive Democratic nominee, Hillary Clinton blasted regulations that allowed a lone gunman to purchase weapons that he used to kill 49 people in Orlando over the weekend -- a slaughter that represented the deadliest mass shooting in U.S. history.

“We may have our disagreements about gun safety regulations, but we should all be able to agree on a few essential things,” Clinton said, speaking to a crowd gathered at the Cleveland Industrial Innovation Center. “If the FBI is watching you for a suspected terrorist links, you shouldn't be able to just go buy a gun with no questions asked.”

Clinton also reiterated comments she made on ABC News' “Good Morning America” on this morning that she would put together a team to track “lone wolf” threats and arguing that “weapons of war have no place on our streets.”

“The Orlando terrorist may be dead, but the virus that poisoned his mind remains very much alive,” Clinton said, adding, “And we must attack it with clear eyes, steady hands, unwavering determination and pride in our country and our values.”

While she avoided mentioning Donald Trump by name, she slammed the presumptive Republican nominee’s proposal to ban Muslims from entering the U.S.

“Inflammatory anti-Muslim rhetoric and threatening to ban the families and friends of Muslim Americans as well as millions of Muslim business people and tourists from entering our country hurts the vast majority of Muslims who love freedom and hate terror," Clinton said.

Today’s event in Ohio was supposed to be a far different event -- a raucous kick-off to her general election campaign, but instead it took on a somber and serious tone.

Clinton called an attack on “any” American, an attack on “all” Americans and encouraged people to “stand together” and be “proud together.”

“I want to say this to all the LGBT people grieving today in Florida and across our country. You have millions of allies who will always have your back,” she said as the crowd cheered. “From Stonewall to Laramie, and now Orlando, we've seen too many examples of how the struggle to live freely, openly, and without fear has been met by violence."

“Originally, I had intended to come to Cleveland under very different circumstances,” she said. “On Sunday, Americans woke up to a nightmare that’s become mind numbingly familiar.”

Before she took the stage, rally attendees held a moment of silence for the 49 victims of the Orlando attack. Former President Bill Clinton also held a moment of silence today at a Clinton Global Initiative meeting in Atlanta.

The former president bowed his heads as the lights dimmed to honor those who lost their lives.

“When something like this happens all of us have a responsibility not only to support those who are trying to call to account those who are responsible and strengthen our defenses but to remember that there is something else we can do," he said. “We can present an alternative view of the future. One that we all share and one where our differences far from being an occasion for murder are a cause for success and a road map to a better future for everyone."

Hillary Clinton postponed a fundraiser in Cincinnati that was planned for after her rally in Cleveland.

ABC's Matthew Claiborne contributed reporting.