The headquarters of an anti-abortion group in Madison, Wis., was set on fire on Sunday morning in an act of vandalism that included the attempted use of a Molotov cocktail and graffiti that read “If abortions aren’t safe then you aren’t either,” according to the police.

No one in the group, Wisconsin Family Action, was in the building at the time, and there were no injuries reported. Although the Molotov cocktail that was thrown through a window failed to ignite, the vandal or vandals started another fire nearby, the authorities said. The fire burned part of a wall.

The Madison Police Department did not say whether it had made any arrests or whether more than one person was involved.

“We have made our federal partners aware of this incident and are working with them and the Madison Fire Department as we investigate this arson,” the department said in a statement.

The attack came nearly a week after the leak of a draft ruling by the Supreme Court that would overturn Roe v. Wade, the landmark decision that established a constitutional right to abortion. Wisconsin has a law banning abortions that predates Roe by more than a century, but Gov. Tony Evers, a Democrat, has said he would block its implementation. Wisconsin Family Action is a nonprofit political advocacy group that promotes conservative policies on several issues, including abortion, within the Wisconsin state government.

“There’s nothing we have done to warrant this. We ought to be able to take different sides on issues without fearing for our lives,” said Julaine Appling, the president of Wisconsin Family Action. “Had anybody been in the office, they would have, at a minimum, been hurt.”

The Madison Fire Department first received a call about the fire at around 6 a.m. on Sunday. Firefighters and police officers arrived shortly after and quickly brought the fire under control. Ms. Appling said that she heard about the attack later in the morning while preparing for a Mother’s Day brunch at her church in Watertown, Wis.

“I got a call from building management here saying there had been a break-in and a fire started,” Ms. Appling said. She then went with a team member to the building, where they discovered “the havoc and property damage.”

Ms. Appling said that her office was the main target of the attack. Two windows had been smashed, and water that was used to put out the fire had caused more damage. Ms. Appling said the graffiti was particularly disturbing. “As I drove up to the office and I saw that, my immediate reaction was surprise at how overt the threat was,” she said. The graffiti included an anarchist symbol and the numbers 1312, a shorthand for an anti-police slur.

Planned Parenthood of Wisconsin also denounced the violence in a statement. “Our work to protect continued access to reproductive care is rooted in love,” the group’s president, Tanya Atkinson, said. “We condemn all forms of violence and hatred within our communities.”

In a statement to The New York Times, Tony Perkins, the president of the Family Research Council, which works with Wisconsin Family Action, attributed the attack to left-wing extremists who aim to intimidate abortion opponents, and he vowed that they would not succeed. “We are grateful for the unwavering leadership of Wisconsin Family Action and the dozens of family policy councils around the country that are committed to the sanctity of all human life,” he added.

Ms. Appling said she and others at the organization had received threats in the past and that she knew that some people would be angry after the Supreme Court draft ruling was leaked.

“I knew automatically that anybody that took a position in favor of how the opinion was written should probably be paying more attention to their safety,” she said. Still, this kind of direct attack was shocking, and she said it had shaken her sense of safety.

She also said she would be working on implementing new security measures in the office.

In a statement on Sunday, the Madison police chief, Shon Barnes, acknowledged the heightened tensions in the community after the leaked draft and condemned the attack.

“Our department has and continues to support people being able to speak freely and openly about their beliefs,” the statement read, “but we feel that any acts of violence, including the destruction of property, do not aid in any cause.”