Amazon Web Services, the cloud computing unit of e-commerce giant Amazon, reported outages with multiple services on Tuesday that caused issues for thousands of customers.

The issues began Tuesday just before noon Pacific Time when customers experienced problems accessing services linked to AWS, including authentication and sign-in errors. Amazon’s engineering teams investigated and found an issue with a subsystem related to AWS Lambda that caused errors directly and indirectly for customers. 

AWS Lambda is used by a number of companies, including T-Mobile, Netflix and Autodesk, according to Reuters.

The website Downdetector.com, which tracks outages by collating status reports from user-submitted errors on its platform, reported a high of around 12,000 reports of outages related to the problem. 

Amazon shares were largely flat in after-hours trading Tuesday in the wake of the outage.

AWS announced at roughly 2:00 p.m. Pacific Time that, "Many AWS services are now fully recovered and marked Resolved on this event. We are continuing to work to fully recover all services."

This is a developing story, please check back for updates. Reuters contributed to this report.