The politically active leader of a US synagogue was found dead with stab wounds outside her home on Saturday, as police cautioned against speculation over the motive for the murder.

Police requested FBI assistance in investigating the murder of Samantha Woll, 40, who presided over the Isaac Agree Downtown Synagogue, which serves metropolitan Detroit.

Police Chief James White urged "that everyone remain patient" while the investigation is underway despite "many unanswered questions."

"It is important that no conclusions be drawn until all of the available facts are reviewed," White said in a statement. "An update … will be forthcoming tomorrow."

The murder came amid escalating tensions in Jewish and Muslim communities across the United States over the Israel-Hamas conflict that has taken thousands of lives this month.

Emergency personnel found Woll dead "with multiple stab wounds to her body," police said. A trail of blood led officers to Woll's nearby home, "which is where the crime is believed to have occurred."

The motive in the killing "is unknown," a police statement added.

The Detroit office of the FBI told AFP in an email that it "will assist the Detroit Police Department as requested."

"We are shocked and saddened to learn of the unexpected death of Samantha Woll, our Board President," the synagogue posted on its Facebook page. "At this point, we do not have more information."

Woll, who led the synagogue since 2022, was also active in Democratic Party affairs, working for US congresswoman Elissa Slotkin and on the campaign of Michigan Attorney General Dana Nessel, the Detroit Free Press said.

"I am shocked, saddened, and horrified to learn of Sam's brutal murder. Sam was as kind a person as I've ever known," Nessel posted on X, formerly Twitter.

Detroit Mayor Mike Duggan said he was "devastated" to learn of Woll's death.

"Just weeks ago, I shared a day of joy with Sam at the dedication of the newly renovated Downtown Synagogue," Duggan posted on X. "It was a project she successfully led with great pride and enthusiasm."

Slotkin, who served as a CIA officer before entering Congress, said Woll sought to build "understanding across faiths, bringing light in the face of darkness."

The Free Press said Woll had been active in a grassroots organization aimed at building ties between young Muslims and Jews.