The shooting that left three police officers dead in Baton Rouge has heightened tensions in Cleveland, where thousands of delegates and tens of thousands of protesters arrived Sunday to a city on edge as it prepares to host the Republican National Convention.

White supremacists, black nationalists and anarchists were among the groups expected to protest over the four-day gathering, and Cleveland police have readied 2,000 riot kits and called in reinforcements from across the nation in case it spirals out of control.

The city had a trial run Sunday when dozens of protesters with a group calling itself "Shut Down Trump and the R.N.C." marched through downtown Cleveland. The bigger test is to come Monday when Citizens for Trump and a group linked to Black Lives Matter plan their first demonstrations around the corner from where the convention takes place.

Worried about the likelihood of more violence in the aftermath of Baton Rouge, the head of Cleveland's largest police union asked Ohio Gov. John Kasich to temporarily suspend the state's open carry gun laws. Kasich denied the request, saying he had no power to do so.

Much of downtown Cleveland was under security restrictions Sunday, with the tightest cordon surrounding the Quicken Loans Arena, where GOP delegates will meet this week to nominate Donald Trump. About 500 Cleveland officers, roughly a third of the city’s force, will be assigned to convention duty, and they’ll be bolstered by 2,500 officers from other states, including Georgia.

Trump’s campaign, which released the schedule of speakers for the convention late Sunday, has designated the theme of Monday night’s opening set of speeches: “Make America Safe Again.” The New York businessman has positioned himself as the “law and order candidate” even as his divisive policies, such as his vow to build a wall on the U.S. border with Mexico, infuriate his critics.

Georgia’s delegation in Cleveland, a contingent that includes about 150 activists and elected officials, was urged Sunday at a briefing to be mindful of their surroundings and not to wear their delegate badges outside of the security cordon lest they be targeted by protesters.

If delegates encounter “hollering and screaming” from protesters outside the arena, GOP chair John Padgett said, act calmly and quickly. “Don’t confront anybody,” Padgett added. “My advice is get on the bus and get in the building.”

Ohio authorities have long prepared for mass protests and the potential of violence at the convention, and dozens of groups scheduled demonstrations months ago to coincide with the convention. Cleveland police drafted plans for mass arrests, arranged for jails to handle an influx of inmates and assigned judges to work late shifts to handle a glut of cases.

But the violence that erupted in recent days has left many in the city even more jittery.

The shooting deaths of two unarmed black men by police officers sparked protests in Atlanta and around the nation over the last week, including a Dallas protest where five police officers were murdered in retaliation. On Sunday, three Baton Rouge law enforcement officials were killed and three more wounded in a hail of gunfire less than a mile from police headquarters.

“You’re always worried about the threat of violence because there’s been such heightened violence,” said Rep. Doug Collins, R-Gainesville, who is part of a 12-member House committee looking at police targeting and police violence.

“We’ve got to take a deep breath – we have to take a collective deep breath in our country on all these issues,” said Collins, who added: “We’ve got to take a step back and say this is our country, blessed with mercy and love, and we have to act with mercy and love.”

Republican Sen. David Perdue, exhorting skeptical Republicans to embrace Trump and “take Georgia out of play” for Democrats, gave a hint of Monday’s theme when he told reporters that strong leadership from a candidate willing to upend the status quo could settle the violent unrest gripping parts of the nation.

“We’ve got to get at the heart of this thing. Disenfranchisement is one thing. Anger is another. We need leadership out of the White House and Washington as well as the statehouses,” he said, adding: “We’ve got to find a way to bring America together again.”