Warren put up her statement in a Facebook post Monday afternoon. In the first 10 minutes after it was posted, the message was shared thousands of times.
Warren has not endorsed in the Democratic presidential primary, although her influence looms large in the race.
Violent confrontations between Trump's supporters and protesters have become commonplace at his rallies in recent months. On Friday, he canceled a planned appearance in Chicago out of safety concerns, saying he had met with law enforcement. The Chicago Police Department responded that it didn't advise Trump to call off the event.
Trump has done nothing to calm his supporters, and has in fact encouraged and applauded people who lash out at protesters. On Sunday, he said he would consider paying the legal fees of a white man who sucker-punched a black man at a recent North Carolina rally.
"[I]n any campaign, responsibility starts at the top," Sen. Ted Cruz (R-Texas) said. "And when you have a campaign that disrespects the voters, when you have a campaign that affirmatively encourages violence, when you have a campaign that is facing allegations of physical violence against members of the press, you create an environment that only encourages this sort of nasty discourse."
He also took the chance, however, to jab at President Barack Obama and lay some of the blame at his feet, saying the president has "sought to divide us on racial lines, on ethnic lines, on religious lines, on class lines."
Editor's note: Donald Trump is a serial liar, rampant xenophobe, racist, misogynist,
This story has been updated to reflect that the Chicago Police Department says it did not advise Trump to call off the rally.