WhatsApp, Facebook and Instagram all went down briefly on Wednesday during a major outage at parent company Meta.
Thousands of app users reported issues accessing the three sites late in the day, with people taking to other social media to air grievances.
Meta's status site later indicated that most issues had been resolved. The company has so far not responded to a request for comment.
Problems began around 18:00 GMT (14:00 EST) on Wednesday.
The UK site Downdetector, which monitors the performance of websites, indicated around 82,000 issues with WhatsApp at 18:25 but an hour later the issue appeared to have been largely resolved.
Users on Instagram reported around 3,700 outages at 18:20, with numbers persisting for a couple of hours.
Similarly, Facebook users advised of issues at the same time with 1,840 outages reported at 18:23.
The technical problem was not confined to the UK - Reuters news agency reported that about 5,000 people faced issues with Instagram in the United States. At its peak, around 24,000 WhatsApp users also experienced problems.
WhatsApp said in a post on the social media platform X, formerly Twitter: "We know some people are experiencing issues right now, we're working on getting things back to 100% for everyone as quickly as possible."
Nearly 3,500 users in India and more than 7,000 in Brazil also reported problems with the platform, according to Downdetector.
In March, hundreds of thousands of users of the social media company's Facebook and Instagram were impacted globally for more than two hours following an outage that was caused by a technical issue.
Meta has about 3.19 billion daily active users across its family of apps, which also includes Threads.
Source: BBC
