Ex-army chief Abdel Fattah al-Sisi won Egypt's 2014 presidential election with 96.9 percent of the vote
Ex-army chief Abdel Fattah al-Sisi won Egypt's 2014 presidential election with 96.9 percent of the vote AFP / Mohamed el-Shahed

Rival hashtags, angry videos and calls to march -- the war for Egyptian minds is raging online ahead of possible mass demonstrations against President Abdel Fattah al-Sisi.

Encouraged by rare protests that erupted last week in Cairo and other Egyptian cities, Sisi opponents have bombarded social media platforms with fiery content under the Arabic-language hashtags #Sisiyouarefinished and #Sisileave.

But they've faced fervent counter-attacks from the president's backers, using #longliveSisi and #theywantchaos.

The internet is the only space in Egypt were the authorities have not yet silenced critics, and in the past week, sites like Twitter and Facebook have morphed into battlefields.

Activists have taken inspiration from a series of viral videos posted on Facebook by Egyptian entrepeneur and actor Mohamed Aly, accusing Sisi and the military of corruption.

His videos, filmed from his exile in Spain and shared millions of times, sparked shock rallies last Friday where protesters clashed with police and called for Sisi's ouster.

Some demonstrated in Cairo's iconic Tahrir Square, the epicentre of the 2011 revolution that toppled dictator Hosni Mubarak.

In his latest video, Aly called for a "million-man march" on Friday, labelling the protests "a people's revolution".

'No leader'

"The call for peaceful demonstrations on Friday is not a call for destruction, devastation and chaos, but a call for hope," Egyptian scientist Essam Heggy, who works in the US with space agency NASA, wrote Thursday on Twitter.

But pro-Sisi politician Mustafa Bakry slammed online opposition activists as "traitors", blaming the unrest on the Muslim Brotherhood -- outlawed as a "terrorist organisation" since 2013 but long one of the country's most organised political forces.

"The Egyptian people will not be the instrument for your return to power," he tweeted.

Mohamed Morsi, a senior Muslim Brotherhood member, became Egypt's first civilian, democratically elected president in 2012.

But the following year, the military -- led by Sisi -- ousted him following mass protests against his divisive rule.

Social media networks played a central role in Egypt's 2011 uprising, but Sisi has tightened internet controls since being elected president in May 2014.

Shortly after Friday's rallies, the popular Facebook Messenger app and news sites were hit by disruptions.

The 2011 uprising was partly triggered by a Facebook page created in solidarity with a young Egyptian tortured to death by police officers in 2010.

Political science professor Mustafa Kamel al-Sayed said that the protests "this time have no leader, they're spontaneous".

But disgruntled businessman Aly's railings against Sisi's alleged graft from exile in Spain have created a focal point for protesters.

Fierce campaign

Pro-government media have launched a fierce campaign against both Aly and the Muslim Brotherhood.

Foreign channels considered close to the Brotherhood, like Qatar's Al Jazeera broadcaster, have also been targets.

On Saudi-run channel MBC Egypt, boisterous pro-Sisi host Amr Adib has slammed Aly and aired footage of him allegedly in a drunken stupor.

Egyptian celebrities and key Sisi backers have also chimed in on social media, posting videos and photos showing their support for the president.

They include famous belly dancer Fifi Abdou, who posted an Instagram clip criticising those she said want to create "chaos" in Egypt.

On Youtube, a video emerged of Egyptian singer Sherine Abdel-Wahab at a concert in Saudi Arabia, where her husband joins her on stage to express their backing for Sisi and the Egyptian army.

In March, the popstar was temporarily suspended from Egypt's musicians union after joking about the lack of free speech in the country.

Last year, she was sentenced to six months in prison but acquitted on appeal after suggesting drinking from the Nile River leads to illness.

Egyptian authorities have arrested more than 1,500 people since Friday's protests, according to rights groups.

The broadening crackdown has also seen prominent critics detained including lawyers, human rights defenders and journalists.