The civilians that make up the Oakland Police Commission voted unanimously Thursday night to fire Oakland (CA) Police Chief Anne Kirkpatrick without cause.

The firing required approval from Mayor Libby Schaaf, who hired the chief three years ago. Moments after the commission's vote, Schaaf phoned the chief to inform her that she was out of the job.

The decision followed a long-simmering tension between the chief and the commission, which was created by a voter-approved ballot initiative in 2016 that aimed to rebuild trust between officers and their community, reports the San Francisco Chronicle .

The commission voted during a closed session of its meeting and announced the action afterward.

"The police commission is the community's voice," Schaaf said in a press conference immediately following the commission's announcement. "The voters of Oakland in 2016 created the most powerful and independent police commission in the country. Tonight they exercised that power."

The termination is without cause, which means the commission isn't obligated to give a reason for ousting Chief Kirkpatrick. While officials addressed the firing on Friday, nothing they said gave any clarification to possible reasons behind the dismissal, reports KPIX .

"We've moved on. We are looking for a new form of leadership and we wish Chief Kirkpatrick well," said Oakland Police Commission Chair Regina Jackson.

On Thursday, Jackson said that a loss of confidence in Kirkpatrick contributed to the decision to fire her.

Mayor Schaaf also briefly spoke about the firing at a basic recruit academy graduation ceremony Friday. "My decision yesterday was extremely personally difficult for me, but I made it because I believe it was in the best interest of Oakland," said Schaaf.

The mayor said it was her duty to determine when the trust between the commission and the chief "has become irrevocably lost and prevents Oakland from moving forward," according to the Chronicle.

Assistant Chief Darren Allison will serve as acting chief until an interim chief is selected. Schaaf said she will do a nationwide search for a new chief.