The majority of high-profile sites are experiencing outages Tuesday afternoon, with no indication what the cause is.

According to DownDetector.com, Google, Google Cloud, Amazon, AWS, Facebook, Instagram, Cloudflare, Spotify, Discord and other are experiencing spikes in reported outages. The reports range from a few hundred to tens of thousands of users.

It’s still too early to know the precise cause, although some sites are already returning to normal.