Following a weekend of violent demonstrations against police brutality across the country and in Austin, President Donald Trump, Texas Gov. Greg Abbott, Austin Mayor Steve Adler and Austin Police Department Chief Brian Manley said much of the violence was stirred by outside groups usurping peaceful protests for their own anarchist aims.

Adler told Community Impact Newspaper that ahead of the weekend’s protests, he received notice from the federal government, relayed through Abbott’s office, that outside groups planned to infiltrate the demonstrations and create violence and chaos.

“We have reports of people coming into town with the demonstration that are not expressing their views on the issue but are being motivated by a desire to cause violence,” Adler said.

Manley said he saw over the weekend what looked like outside groups invading peaceful demonstrations and turning them violent. As of midday June 1, Austin police arrested 53 people in relation to the protests. Manley said he did not have data yet on where the arrested protesters hail from. Manley’s department unloaded tear gas, pepper spray and “less-lethal” bean bag rounds—fired from a shotgun—during clashes with demonstrators over the weekend.

“This is protesting that we have not seen here before in Austin before,” Manley told reporters June 1. “This was a very difficult weekend to manage the protests as they moved around the city and to try and limit the amount of damage, the vandalism, the looting that was taking place. The goal, the emphasis, the purpose of the Austin Police Department was to preserve the safety of those ... that were out there trying to protest peacefully ... but unfortunately we had people move into the crowd that were taking dangerous actions against officers, and we had to respond and try to put a stop to that activity.”

Abbott’s office released a statement June 1 that said any protesters arrested for “looting, violence or other acts of destructive acts in violation of federal law” would be subject to federal prosecution. Abbott said four U.S. attorneys will be working with local prosecutors to “aggressively identify” crimes that violate federal law.

“Texans must be able to exercise their First Amendment rights without fear of having agitators, including those coming from out-of-state, hijack their peaceful protest,” Abbott said in a statement. “Today’s announcement will ensure there are harsh consequences for those breaking the law and that they will be prosecuted to the fullest extent of the law.”

Manley said he “absolutely” supported Abbott’s order.

“I think if you are traveling to other communities and going to other states for the purpose of riotous behavior, especially when you’re overtaking what is meant to be, and what needed to be, peaceful protesting and community activism, at a time when we need it the most, I absolutely support [Abbott’s order],” Manley said. “That is unacceptable. When your purpose is to detracting from a community that is trying to come together, that is trying to heal, that is trying to learn, and you’re coming in, and you’re disrupting that.”

The Austin Justice Coalition canceled its own peaceful demonstration at the last minute, planned for outside the Texas Capitol on May 31, after its executive director, Chas Moore, said he could no longer guarantee the safety of protesters due to outside groups “co-opting” the moment to spread violence and chaos.

Addressing the country in the White House Rose Garden on June 1, Trump also railed against the violence exhibited by protesters across the country over the weekend before urging governors across the country to call the U.S. National Guard in to quell the chaos, threatening to send in the military if cities devolve further into chaos.

“We cannot allow the righteous cries of peaceful protesters to be drowned out by an angry mob,” Trump said. “[I’m an ally] of all peaceful protesters, but, in recent days, our nation has been gripped by professional anarchists, violent mobs, arsonists, looters, criminals, rioters, antifa, and others. A number of state of local governments have failed to take necessary action to safeguard their residents."

The protests against police brutality, spurred nationwide by the killing of George Floyd, an unarmed black man, by Minneapolis police on May 25, and locally by the April 24 killing of Michael Ramos, an unarmed black man who was shot three times with a rifle by an Austin police officer, are expected to continue through the week.