Pop queen Beyoncé penned an open letter Thursday in response to the police-involved shooting deaths of Alton Sterling and Philando Castile this week, in which she begged law enforcement officers to “stop killing” black people.

“We are sick and tired of the killings of young men and women in our communities,” the Lemonade singer wrote in a letter posted to her website. “It is up to us to take a stand and demand that they ‘stop killing us.'”

The letter comes in response to two high-profile police-involved shootings this week. Alton Sterling was shot and killed by Baton Rouge police on Tuesday in an incident caught on camera, while on Wednesday, a Minnesota police officer fatally shot Philando Castile. The latter incident was live-streamed in a widely shared Facebook video.

“We’re going to stand up as a community and fight against anyone who believes that murder or any violent action by those who are sworn in to protect us should consistently go unpunished,” Beyonce’s letter continues. “These robberies of lives make us feel helpless and hopeless but we have to believe that we are fighting for the rights of the next generation, for the next young men and women who believe in good.”

The Grammy Award-winning singer adds: “Fear is not an excuse. Hate will not win. We all have the power to channel our anger and frustration into action. We must use our voices to contact the politicians and legislators in our districts and demand social and judicial changes.”

Beyoncé has increasingly weighed in on politically-charged issues around race and policing.

The lead single for Beyoncé’s latest album, Lemonade, was the song “Formation” — a pro-Black Lives Matter anthem. The video for the song featured the singer dancing atop a submerged police cruise, and also featured a scene showing a graffiti-tagged wall bearing the words “STOP SHOOTING US.”

Beyoncé also performed a Black Lives Matter-inspired Super Bowl halftime show in February that paid tribute to the anti-law enforcement Black Panther Party. The performance spurred numerous protests by law enforcement organizations around the country and included threats to boycott several of her tour stops, including in Miami, Pittsburgh and Arlington, Texas.

Beyoncé took to Instagram Thursday to share her statement with her 77 million followers.

“We all have the power to channel our anger and frustration into action,” she wrote.

Follow Jerome Hudson on Twitter @jeromeehudson