Groups of protesters gathered in several Egyptian cities beginning late on Friday in response to an online call for a demonstration against government corruption.
Egyptian security forces clashed with hundreds of anti-government protesters in the port city of Suez on Saturday, firing tear gas and live rounds, said several residents who participated in the demonstrations.
A heavy security presence was also maintained in Cairo's Tahrir Square, the epicentre of Egypt's 2011 revolution, after protests in several cities called for the removal of general-turned-president Abdel Fattah al Sisi.
Such demonstrations are rare after Egypt effectively banned protests under a law passed following the 2013 military ouster of ex-president Mohamed Morsi.
But discontent over rising prices has been swelling in Egypt, where Sisi's government has imposed strict austerity measures since 2016 as part of a $12-billion loan package from the International Monetary Fund.
Nearly one in three Egyptians live below the poverty line on less than $1.40 a day, according to official figures released in July.
On Saturday, protesters headed to downtown Suez for the second night in a row, where they were met by security forces barricading the streets and armoured vehicles.
"There were about 200 or so people. They (security forces) fired tear gas, rubber and live bullets and there were injuries", a man who took part in the demonstration but declined to be named told AFP.
Another resident, who also preferred to remain anonymous, said the tear gas was so thick it had reached her apartment block a few kilometres away from the turbulent downtown area.
"My nose started burning up. The smell was seeping through the balcony. I also saw some youth run and hide in our street", the woman said.
On late Friday, hundreds of Egyptians poured through the streets of Cairo, chanting slogans including "Leave, Sisi!" and demanding the "fall of the regime".
At least 74 people were arrested after clashes between the crowds and police in the capital, a security source told AFP.
The protests came after Mohamed Aly, an exiled businessman and opponent of Sisi posted calls online for demonstrations against Sisi.
He upped the pressure on Saturday in an expletive-filled video, imploring Egyptians to join a "million-man march" next Friday and to fill all "major squares" of the country.
"This is a people's revolution...We have to link up together as one...and organise going down to the major squares," he said in a Facebook appeal to his followers.
The construction contractor has been posting videos that have gone viral since early September, accusing Sisi and the military of rampant corruption.
The president denied the allegations last week, saying he was "honest and faithful" to his people and the military.
But on Friday demonstrators took to the streets in Cairo after a highly-charged football match between local powerhouses Al Ahly and Zamalek.
"I think it's safe to say that the events of the past few weeks, including the development last night, pose the most serious legitimacy crisis facing Sisi," Nael Shama, a Cairo-based political analyst, told AFP.
"No one shouted bread, freedom, social justice like in 2011, they escalated straight to 'Leave' from the first minute," Shama noted.
On social media, thousands shared footage of Friday's demonstrations, which sprang up in several cities, including sizeable crowds blocking traffic in Alexandria, Al-Mahalla, Damietta, Mansoura and Suez.
"This is the first time people take to the streets in many years but I am not sure it will be the last," Shama added.
Under Sisi's rule, authorities have launched a broad crackdown on dissidents, jailing thousands of Islamists as well as secular activists and popular bloggers.
Sisi has regularly invoked security and stability as hallmarks of his reign in contrast to regional hotspots such as Libya and Syria.
'Ball in government's court'
The government's foreign media accreditation body released a statement late Saturday cautioning international journalists that their reporting of events "should not be exaggerated", without explicitly mentioning the protests.
On television Friday night, boisterous pro-Sisi host Amr Adib lambasted Aly, the businessman, showing footage of him allegedly in a drunken stupor.
Adib urged his fellow countrymen to "take care of the country...because the Muslim Brotherhood want to raze it to the ground".
The Islamist group, once considered one of Egypt's most organised political forces, was outlawed as a terror group in 2013 after Morsi's overthrow.
Sisi is in New York where he is scheduled to address the UN General Assembly next week. His office did not comment on the protests when asked by AFP on Saturday.
"Now the ball is in the government's court," said Shama, the analyst. "They have to respond somehow."