Sri Lanka blocked several social media networks in the wake of terrorist attacks on Sunday, including Facebook and the messaging service WhatsApp.
YouTube, Instagram, Snapchat and Viber were also inaccessible, according to internet monitoring groups.
Tourists and residents attempting to get in touch with relatives via social media on Monday were unable to do so without a Virtual Private Network (VPN) or a foreign SIM card, after the government ordered a block on social media in the aftermath of the attacks.
Attempts to load Facebook, Instagram, WhatsApp and the messaging app Viber all failed Monday morning. Twitter appears to be accessible and some government ministers have been tweeting out information.
Some Sri Lankans have been circumventing the blocks with VPNs. People using foreign SIM cards which roam onto non-Sri Lankan networks were unaffected.