Facebook is denying allegations that it intentionally removed a video after a black man was shot and killed by a police officer in Minnesota, and is instead blaming its disappearance on a glitch.

Diamond Reynolds began live-streaming a video on Facebook after her fiancée, Philando Castile, 34, was shot by police in his car on Wednesday. He later died of his injuries.

The video quickly went viral and reached more than 1 million views, but then suddenly disappeared from Facebook for about an hour.

In a statement to the website TechCrunch, Facebook denied that it censored the video and instead blamed the situation on a malfunction.

“We’re very sorry that the video was temporarily inaccessible. It was down due to a technical glitch and restored as soon as we were able to investigate,” a Facebook spokesperson said.

The video reappeared on Facebook about an hour later, and now includes a warning before viewers watch it.

Facebook founder Mark Zuckerberg responded to Castile’s death on his personal Facebook page, but he did not comment on the unusual glitch or the video’s brief disappearance.

“My heart goes out to the Castille family and all the other families who have experienced this kind of tragedy. My thoughts are also with all members of the Facebook community who are deeply troubled by these events,” Zuckerberg wrote.

“The images we've seen this week are graphic and heartbreaking, and they shine a light on the fear that millions of members of our community live with every day. While I hope we never have to see another video like Diamond's, it reminds us why coming together to build a more open and connected world is so important -- and how far we still have to go.”

Castile was shot and killed just a day after Alton Sterling was pinned to the ground by two police officers and fatally shot at close range in Baton Rouge, Louisiana. Sterling’s death was caught on camera, and U.S. Justice Department has launched an investigation into the killing.

Facebook’s livestreamed videos are one of the website’s newest user capabilities. The feature last gained widespread attention in May after the so-called Chewbacca mom, Candace Payne, was filmed trying on a Star Wars mask in her car.