Amazon.com's cloud service division Amazon Web Services says it is investigating an issue where users attempting to access AWS signup were receiving error messages.
Hundreds of users reported issues with accessing Amazon Web Services on Sunday, according to outage-tracking website Downdetector.com.
Amazon's voice assistant Alexa was also down for thousands of users in the United States, according to Downdetector.com.
More than 15,000 users reported issues with Alexa at the peak of disruption, Downdetector data indicated.
Users also reported issues accessing Amazon's mobile app.
Amazon did not immediately respond to Reuters queries on reasons for the outage and estimated timeline for resolution.
Downdetector tracks outages by collating status reports from several sources, including user-submitted errors on its platform.