MINNEAPOLIS, United States (AFP) — US immigration agents may have breached “protocol” in Minneapolis before shooting dead a nurse during protests, a senior White House aide said on Tuesday, as President Donald Trump suggested he would “de-escalate a little bit” in the city.

The comments came the same day a man sprayed Minnesota Congresswoman Ilhan Omar with a syringe of unknown liquid at a Minneapolis town hall meeting, where she called for curbing the Trump administration’s immigration crackdown.

White House Deputy Chief of Staff Stephen Miller told Agence France-Presse the administration is evaluating whether the Customs and Border Protection (CBP) agents who gunned down 37-year-old Alex Pretti on Saturday failed to follow “clear guidance” to “create a physical barrier between the arrest teams and the disruptors.”

“We are evaluating why the CBP team may not have been following that protocol,” Miller said in a statement, though the White House later said Miller was referring to “general guidance” to immigration agents in Minnesota.

Trump, meanwhile, told Fox News that the administration was “going to de-escalate a little bit” its operations in Minneapolis, adding that the plan was not a “pullback.”

He admitted that Gregory Bovino, a hardline Border Patrol commander who is now expected to leave the city, was “a pretty out-there kind of a guy” whose presence may not have helped the situation. He sent top US border security official Tom Homan to meet with officials there.

Trump also told reporters that he rejected the “assassin” label previously used by Miller to describe Pretti, adding that he wants “a very honorable and honest investigation.”

Still, tensions remained high in Minneapolis after Omar, a Democratic congresswoman, was attacked by a man at a constituent town hall Tuesday night.