Instagram was restored online after experiencing global outages, the social media company said.
Down Detector, a website that tracks outages, reported 56,628 reports at around 11pm on Sunday.
The Down Detector location map showed the outages spread across the UK with reports of outages coming from the US and Australia as well.
Instagram said at 1.19am on Monday that the issue which had caused the outage had been resolved.
The photo and video networking service appeared to be online again before 1am with reports of the outages dropping to less than 500 by 1:..
According to Down Detector, 92% of the outages were on the app, 6% via the website and 2% on the login.
Users could not refresh their feed or post during the outages.
It came after Instagram experienced an outage on March 9 where thousands of users reported similar issues.