EGYPT HAS BLOCKED almost all internet access within its borders, in attempts to stop activists from using sites like Facebook and Twitter to organise further anti-government protests in the country.

Users this morning woke to find almost all sites inaccessible, with access being slow and intermittent for most users, while mobile phone services also appeared to have been disrupted in downtown Cairo.

Both Facebook and Twitter had confirmed that their sites had seen traffic disrupted from the country; a Facebook statement said it was aware of reports of disruption, and it had seen “a drop in traffic from Egypt this morning”.

The tactic came as the country prepared for the largest anti-government demonstrations to date, with protesters further incensed by the death yesterday of a fifth demonstrator, who was shot dead by security forces in the north of the country.

The Muslim Brotherhood, the largest opposition party in the country, has offered its official backing to today’s planned protest, while the Wall Street Journal reports that Nobel laureate Mohamed ElBaradei – a secular activist who commands large public attention – has returned to the country to participate.

The demonstrations in the Arab world, meanwhile, have spread to Yemen – one of the most impoverished countries in the Middle East – where thousands took to the streets yesterday to call for the overthrowing of President Ali Abdullah Saleh.

“People want to change the regime, want the president to leave,” Xinhua quotes protestors as roaring.

Demonstrators there have taken to the streets wearing pink headbands and waving pink flags, in scenes echoing those of Tunisia, where the recent overthrow of President Ben Ali has been dubbed the ‘jasmine revolution’.