The WhatsApp messaging platform is now back online after an outage affecting many of its two billion users around the world.
Meta, or Facebook, which owns WhatsApp, said the problem had been fixed, said reports.
But the company did not give a reason for the disruption.
Users trying to send or receive messages noticed problems from 8am.
According to one report, more than 12,000 reports were posted within 30 minutes. The figures were attributed to the website Down Detector.
But the issue was resolved by 10am.