Q&A: Egypt's new protests
After deadly clashes between demonstrators and security forces in Egypt, the BBC news website looks at what lies behind the latest round of protests.
Why are the protesters back?
Protesters are angry at the slow pace of reforms and are demanding the end of military rule. While many welcomed the hand-over of power to the army after President Hosni Mubarak stepped down in February, disenchantment has steadily risen.
The ruling generals are all appointees of Mr Mubarak and have been overseeing the rocky transition to democracy for the past nine months. Activists feel they have failed to dismantle remnants of the old regime or deal with the faltering economy and festering social problems, seeking instead to consolidate their hold on power.
There have been signs that the military is seeking to oversee the priority for the next parliament - the formation of a committee to draw up a new constitution. The Supreme Council of the Armed Forces (Scaf) is seeking to have veto power over this body, to enjoy a special role as "protectors" of the constitution and to insert provisions that would keep the defence budget a secret.
Who are the demonstrators?
Dissatisfaction is highest among the youth groups that joined the anti-Mubarak revolution and feel they have been marginalised and isolated. Liberals have long expressed grievances with the army, which has put 12,000 civilians on trial in military courts and is accused of torturing detainees.
Islamists have also been raising their voices, including the Muslim Brotherhood, who expect to be the main winners of planned parliamentary elections. They fear the military will try to retain some control.
Many protesters are sceptical about the commitment by Field Marshal Tantawi in his speech on Tuesday to hold presidential elections by the end of June 2012.
A growing number have been calling for him to step down immediately along with the Scaf, in favour of an interim civilian council. They also want a full inquiry into the latest violence.
The demonstrators insist they will remain in Tahrir Square, the symbolic heart of the Egyptian revolution, until their demands are met. While the military has permitted mass rallies there, it has repeatedly acted to prevent long-term sit-ins that close down the centre of the capital.
Can an election happen now?
The first parliamentary elections to be held after the revolution are due to begin on 28 November and last for several months.
Before the current unrest, concerns were already being raised about whether security could be guaranteed during the long, complicated process of voting. The latest protests and the bitter atmosphere that accompanies them throw that further into doubt.
The ruling military has insisted that it is sticking to the timetable for the parliamentary elections and has appealed to the newly formed political parties, which have been preparing for the vote, to help clear the square and contain the situation.
Is there a way out?
It is hard to predict exactly what will happen now. Emergency meetings have been taking place among the ruling generals on how to proceed. So far they have found that brute force only intensifies activists' anger. The interim cabinet's decision to submit its resignation is a sign of how tough their position has become.
A big test for the protesters is whether they can again draw out the huge numbers that were seen in Tahrir Square during the revolution. This would increase pressure on the military to meet their demands.