WASHINGTON (AP) — The leak of a draft Supreme Court opinion striking down the constitutional right to abortion has unleashed a wave of threats against officials and others and increased the likelihood of extremist violence, an internal government report says.

Violence could come from either side of the abortion issue or from other types of extremists seeking to exploit tensions, according to a memo directed to local government agencies from the Department of Homeland Security's Office of Intelligence and Analysis.

It's an added element to what is already a volatile environment in the U.S., where authorities have warned repeatedly over the past two years that the threat posed by domestic extremists, such as the gunman who committed the racist attack over the weekend in Buffalo, has surpassed the danger from abroad.

The memo, dated May 13 and obtained Wednesday by The Associated Press, seeks to differentiate between illegal activity and the intense but legal outpouring of protests that are all but guaranteed when the Supreme Court issues its ruling at the end of its term this summer, regardless of the outcome.

"DHS is committed to protecting Americans' freedom of speech and other civil rights and civil liberties, including the right to peacefully protest," the agency said in a written response to questions about the memo.

Those protests could turn violent. The memo warns that people "across a broad range of various ... ideologies are attempting to justify and inspire attacks against abortion-related targets and ideological opponents at lawful protests."

Violence associated with the abortion debate would not be unprecedented nor would it necessarily be confined to one side or the other, the memo says.

Opponents of abortion have carried out at least 10 killings as well as dozens of arson and bomb attacks against medical facilities in their long campaign to overturn Roe v. Wade.

DHS said there is also a potential for violence from the other side, citing recent damage to buildings used by abortion opponents in Wisconsin and Oregon.

"Historically, violent acts related to this issue were primarily committed by abortion-related violent extremists that opposed abortion rights," it said. "Going forward, grievances related to restricting abortion access could fuel violence by pro-choice abortion-related violent extremists and other" (domestic violent extremists).

In the Wisconsin incident, it noted, the building was set on fire and the perpetrators left graffiti that said "If abortions aren't safe (then) you aren't either."

The leak of the opinion this month, authorities prompted a "significant increase" in threats through social media of Supreme Court justices, members of Congress and other public officials as well as clergy and health care providers, the memo said.

At least 25 of those threats were forwarded to law enforcement agencies for further investigation.

The Justice Department announced Wednesday that the U.S. Marshals Service has the justices under 24-hour security.