San Francisco, Apr 14 (IANS): Exactly a month after Facebook and its family of apps suffered its longest -- almost 24 hours -- world-wide outage, WhatsApp, Instagram and Facebook users from around the world on Sunday were again complaining that the apps were not working properly.

The outage appeared to have started around 6.30 a.m. Eastern Time, 4 p.m. in India, The Verge reported.

Users took to other social networking platforms, like Twitter, and complained that the News Feeds on the apps were refusing to refresh. Though it remained unclear how many regions in the world were experiencing issues with Facebook-owned apps, #FacebookDown was trending on Twitter.

"Confirmed: Analysis of global network data shows Facebook, WhatsApp, Instagram and Messenger down globally for an estimated 60 per cent of users; incident ongoing #FacebookDown," cybersecurity firm NetBlock.org tweeted.

Facebook's instant messaging service WhatsApp also reported to have stopped sending or receiving messages. "In addition, the main Facebook.com domain is also seemingly unavailable," the report said.

Apologising for the outage in March, the social networking major had blamed a "server configuration change" for the trouble in accessing its apps and services.

However, it has not yet addressed what appears to be another mass outage for its apps.