Ahmad Al-Rubaye/AFP via Getty Images

Internet access has been blocked across most of Iraq as mass anti-corruption protests continued into their third day. Internet access watchdog Netblocks reports that the blackout began with social media platforms on Wednesday and spread until roughly 75% of Iraq's internet, including in capital city, Baghdad, was shut down Thursday morning.

The shutdown didn't affect the autonomous Kurdish region in the north, which uses a different system to get online, according to Netblocks.

"On Wednesday afternoon, WhatsApp and Facebook Messenger remained partially usable via mobile phones on some of the affected networks for some time. This is due to circumvention measures and alternative messaging protocols built into recent versions of the mobile apps," Netblocks said in a blog post.

Government officials also imposed a round-the-clock curfew Thursday, as reported by Reuters. Both moves follow a growing number of political demonstrations during which 20 people have been killed, including one police officer.

Internet access was cut off last year during similar protests in southern Iraq. As with other blackouts, the shutdown began with social media platforms and spread to other sites.

Iraq's US embassy didn't immediately return CNET's request for comment.