Some 1,500 active-duty soldiers have been placed on standby for possible deployment to Minneapolis, a defense official confirmed to CBS News, as tensions in the city have mounted after a woman was fatally shot by a U.S. Immigration and Customs Enforcement officer.

Deploying the soldiers, from the 11th Airborne Division at Fort Wainwright in Fairbanks, Alaska, is one option for which the military is planning in case President Trump decides to use active-duty military personnel to respond to the ongoing demonstrations, the official said. No decision has been made on whether to deploy the soldiers.

ABC News was first to report that the soldiers were on standby.

Minnesota Gov. Tim Walz also mobilized the state's National Guard on Saturday, although guard members had not yet been deployed to city streets, CBS News Minnesota reported. Walz had issued a warning order earlier this month to prepare guard members for mobilization, after an ICE officer shot and killed Renee Good on Jan. 7.

"We are doing the work to keep people safe in our city, and, specifically, it is our local police officers, it is the state of Minnesota and our governor," Minneapolis Mayor Jacob Frey said on "Face the Nation with Margaret Brennan" on Sunday. "We are doing everything possible to keep the peace, notwithstanding this occupying force that has quite literally invaded our city." 

In addition to the immigration agents, Mr. Trump on Thursday threatened to invoke the Insurrection Act, a law dating back to the 1790s that would allow him to send federal troops into Minneapolis. The president said he would invoke the act if Minnesota politicians "don't obey the law and stop the professional agitators and insurrectionists from attacking the Patriots of I.C.E., who are only trying to do their job." 

That move could catalyze a major escalation in the tensions between Minnesota officials and the federal government, which had already sent thousands of federal law enforcement agents to the state in recent weeks as part of the Trump administration's immigration crackdown.

Mr. Trump has threatened to invoke the Insurrection Act before, during his first term and previously during his current one, but he has never actually used it. 

The Minneapolis Police Department said Saturday that demonstrators had remained peaceful and lawful in the presence of federal immigration agents, CBS Minnesota reported.

"Today, when crowds blocked roadways, vehicles were used to block roadways, MPD deployed resources and made public announcements for people move to the sidewalk or out of the area. This occurred several times. In general, crowds were responsive to those directives," the department said in a statement, urging community members involved in the protests to continue to demonstrate peacefully.