Rep. Maxine Waters, D-Calif., whose call for public protests of Trump administration officials has triggered a debate over civility in politics, said Thursday that she has canceled events in Texas and Alabama this weekend due to a "very serious death threat" made against her.

In a statement reported by CNN, Waters said that after President Donald Trump took aim at her on Twitter on Monday, "even more individuals are leaving threatening messages and sending hostile mail to my office."

"There was one very serious death threat made against me on Monday from an individual in Texas which is why my planned speaking engagements in Texas and Alabama were canceled this weekend," Waters said in the statement.

A Waters spokeswoman did not immediately respond to a request for confirmation.

Waters had been scheduled to speak Saturday morning at the annual legislative conference of the National Organization of Black Elected Legislative Women in Birmingham, Ala. The organization's president, Karen Camper, told the Montgomery Advertiser that Waters had canceled her appearance due to security concerns.

The details of Waters' Texas event were not immediately known.

Waters has been rebuked by Republicans and Democrats alike after calling at a Los Angeles rally last weekend for demonstrators to harass Trump's Cabinet officials wherever they go amid an escalating debate over immigration policy.

Taking to Twitter, Trump fired back by calling Waters "an extraordinarily low IQ person" and ominously warning her to "be careful what you wish for."

According to CNN, Waters said in the statement that U.S. Capitol Police are investigating several other threats in which people have vowed "to shoot, lynch, or cause me serious bodily harm." A Capitol Police spokeswoman did not respond to a request for comment.

The news comes on the same day that a gunman opened fire in the offices of the Capital Gazette newspaper in Annapolis, Md., killing five people and gravely injuring several others.