The NetBlocks observatory said it detected an intentional blackout of services such as Facebook, YouTube, WhatsApp, Instagram, Snapchat and Viber.
The defense ministry said the shutdown would expand until the government concludes its investigation into the bomb blasts that rocked churches, luxury hotels and other websites.
NetBlocks cautioned that these post-attack blackouts are often ineffective.
“What we’ve noticed is that when social media is shut down, it creates a vacuum of information that’s readily manipulated by other parties,” said Alp Toker, executive manager of the London-based group. “It can add to the sense of fear and can cause panic.”
The team said its monitoring of Sri Lankan net connectivity discovered no disruptions to the basic infrastructure of the world wide web, meaning the blackout was directed at particular services. Some social media outlets, for example Twitter, appeared untouched, but the blockage affected popular messaging solutions.
“That is going to be a problem for people attempting to communicate with friends and family,” Toker said.
Some internet users are bypassing the societal networking cubes using a virtual private network, which pushes the location of a computer, Toker said.
It isn’t the first time Sri Lanka has blocked societal media. The authorities imposed a weeklong ban in March 2018 due to concerns that WhatsApp along with other platforms were being used to fan anti-Muslim violence in the country’s central region.
An analysis by Sri Lankan researcher and writer Yudhanjaya Wijeratne of tens of thousands of Facebook articles made during this past year’s ban found that many Sri Lankans just found ways about it. Wijeratne has recommended more and more”technically difficult” approaches to controlling hate speech, such as better detection and strengthening regulations.
Facebook, which possesses WhatsApp and Instagram, has struggled in recent years to fight the use of its platforms to incite violence and spread hate messages and political propaganda in countries such as India, Myanmar and the United States.
“We’re conscious of the government’s statement concerning the temporary blocking of societal media platforms,” the company said. “People rely upon our solutions to speak with their loved ones and we are dedicated to preserving our services and helping the community and the country during this tragic time.”
Google did not respond to a request for comment about the disturbance to its own YouTube service in Sri Lanka. Requests for comment made to messaging services Snap and Viber weren’t returned Sunday.