(Reuters) - Microsoft ( MSFT )-backed OpenAI said on Friday night it is facing an issue that has resulted in its popular chatbot ChatGPT being unavailable.

The company said in a statement on its website that it was investigating the issue and working to restore functionality as soon as possible.

Over 19,403 users had been impacted by the outage as of 7:13 p.m. ET (0013 GMT on Saturday), according to outage tracking website Downdetector.com.

OpenAI did not immediately responded to a request for comment.