Update: Twitter, Facebook reportedly inaccessible

Tens of thousands of demonstrators took to the streets across Egypt Tuesday, facing down a massive police presence to demand the ouster of President Hosni Mubarak in protests inspired by Tunisia's popular uprising.

Gamal Mubarak, son of President Hosni Mubarak, had fled the country along with his family, according to the Adnkronos International news service.

Demonstrators calling for economic and political reforms broke through police barriers and began marching in Cairo's streets.

Protesters gathered outside the Supreme Court in downtown Cairo and held large signs that read "Tunisia is the solution" amid massive police deployment, an AFP correspondent said.

Chanting "Down with Mubarak" -- in reference to Egyptian President Hosni Mubarak who has been in power for three decades -- they broke through several police cordons and began marching towards Tahrir Square, in scenes seldom witnessed in Egypt.

Others shouted "Tunisia is not better than Egypt" as the crowds began to swell.

A security official told AFP that at least 20,000 to 30,000 police had been mobilized in the center of the capital alone, and that the area housing the interior ministry had been sealed off.

In a stunning video released Tuesday, one protester was seen standing his ground against a mobile water cannon.

Twitter reportedly inaccessible

Twitter was inaccessible in the country in what was believed to be a move to thwart protesters using the social network in their campaign to oust Mubarak.

The US-based microblogging service that allows people to use mobile phones to broadcast short text messages was out of service in Egypt on Tuesday, according to the herdict.org tracking website recommended by Twitter.

A Twitter spokesman declined to comment on what was causing the service outage in Egypt.

"Egypt is going wild and I'm not sure we'll really have a sense of it until the dust clears," Digital Democracy's Mark Belinsky told CNET. "Hard to say whether or not it's just getting overloaded though...(physically severing) Internet was done in Burma after a while but it usually leads to international uproar. What they generally do is slow down the signal to a crawl, as they did in Iran, which they can then say was infrastructure failure or any other made up excuse."

"It would be an interesting and desperate move for Egypt because their state security apparatus has been very good at infiltrating communication instead of blocking it," he added. "They go so far as to ask for the passwords to the e-mail accounts of dissidents and log-ins for their Web sites instead of censoring them. There are some tech-savvy youth there, hence tweeting through proxies as soon as they encounter some difficulties. But after a critical mass, organizing is done more on the streets than online and the authorities already know the details about who the key organizers are in the crowd."

The protest, called by the pro-democracy youth group the April 6 Movement, coincided with a national holiday to mark Police Day.

Update: Facebook blocked

Reports Wednesday indicated that Egyptian authorities had also moved to block Facebook.

"If Facebook has in fact been blocked, this isn’t particularly surprising. Facebook itself has also been actively used to organize the demonstrations in Egypt. For instance, one Facebook Group called We Are All Khaled Said, features up-to-the-minute updates on the protests and photos from the scene," Techcrunch wrote.

Said was "a young man brutally tortured and killed by police in Alexandria," according to the Foreign Policy blog.

-- With AFP

This video of protesters literally chasing riot police through Cairo's streets was published to YouTube on Tuesday, Jan. 25, 2011.