The reason for the shutdown is unclear, but speculation is that the government has blocked social media sites to prevent people from using them to organise protests that could disrupt Independence Day celebrations on 24 May.
Discontent about the lack of political reform is growing in Eritrea, a one-party state ruled by President Isaias Afwerki since independence in 1993.
According to Internet World Stats, Eritrea has one of the lowest internet penetrations in the world. In 2018, it had only 71,000 internet users. They made up 1.3% of the population.
Communication in Eritrea is strictly controlled by the government. There is no private media, and the internet cannot be accessed via mobile phones.