Twitter has confirmed it has been blocked in Egypt.
In Cairo, thousands of people have taken to the streets and fighting the riot police to protest President Hosni Mubarak’s 30-year rule.
The demonstrators are said to have been inspired by the Tunisian uprising that ousted President Zine el-Abidine Ben Ali on 14 January.
Reportedly, Twitter and Facebook were among Internet social networking services that were being used by protesters to share information and coordinate activities.
As it confirmed the blocking of its service, the Internet messaging and communications site said the open exchange of information and views benefits societies and helps governments better connect with their people.
Harvard’s Berkman Center for Internet & Society project coordinator Jillian York said in an email that she had "confirmed with users in Egypt that Twitter.com is in fact blocked on all ISPs."