More than half a million secondary school pupils are retaking their baccalaureate exams in Algeria after a major leak of the papers online earlier this month.
Algerian authorities have decided to temporarily block several social media websites including Facebook and Twitter, starting on Sunday, to prevent further cheating.
A total of 555,177 pupils will be resitting partial baccalaureate exams from June 19 to 22.
The Ministry of National Education said "all measures have been taken to ensure the smooth running of the exams, in collaboration with other sectors concerned, namely the National Police, National Gendarmerie, Civil Protection and Health authorities".
Authorities reportedly arrested dozens of people, including officials working in national education offices and printers, earlier in June, as part of an investigation into how parts of the 2016 high school exams were leaked onto social media.
In a statement on Sunday, the Ministry of Post, Information Technology and Communication said the "cut of social networks has a direct relationship with the matriculation exams".
The ministry said the unusual move was made to protect pupils from "phony topics" that might appear on social media.
It added that all other parts of the internet were not affected.
Access to the internet through the 3G mobile network, however, appeared to be disrupted.