Masr el-Gedida district's chief prosecutor Ibrahim Saleh has ordered a four-day detention period for eight suspects accused of attempting to torch Ittihadiya presidential palace with petrol bombs.
Eleven other people have also been detained as investigators build evidence in relation to clashes between security forces and anti-government protesters outside the monument in Cairo.
Saleh has ordered a technical review of the fires lit at the palace and has left the door open for the potential arrest of security officers for questioning.
All 19 suspects have denied the charges and claim they were arrested as they innocently walked past the palace, without any involvement in the protests.
Egyptian forces have continued to build barbed wire barriers around Ittihadiya palace, and increased the height of a brick wall surrounding the presidential headquarters.
On Saturday, there was a air of calm in the capital, as traffic returned to normal on the streets that were blocked by protesters on Friday.
President Mohammed Morsi met a delegation from the Salafist al-Nour Party, comprising the chairman Younis Makhyoun, deputy-chairman Sayed Khalifa and secretariat Galal Morra. The meeting was focused on the party's proposals for resolving the recent political tension.
Morra revealed that the meeting was held due to a "sense of responsibility towards Egypt, especially in these difficult times when the political and economic crises have merged."
He also stressed his party's faith in dialogue as the only possible solution to "the current state of conflict and polarisation being witnessed on Egyptian streets."
"The party is moving towards a state of political stability that paves the way for parliamentary elections. We are confident that with our success, Egypt can move on from the maelstrom of transitions and enter a period of stable governance that could fulfil the revolution's demands," the Salafist official said.
Opposition bloc, the National Salvation Front [NSF] also held a meeting to discuss recent developments and the state of the Egyptian economy.
After the meeting, NSF member Sameh Ashour read a statement at a media conference in which he said the opposition group discussed the current government's failure to limit the suffering of the Egyptian public as well as the continued decline of the Egyptian pound, which has reached its lowest value.
The security situation was also discussed at the meeting, Ashour said, with NSF holding the President and Interior Ministry responsible for the breakdown in law and order, and the increase in rape and torture cases.
Regarding recent statements by hard-line Islamists which called for the killing of NSF members, Ashour said such "extremist fatwas" amount to "incitement to murder, which is punishable by law." He demanded that the state takes measures to end the violence and confronts the fatwas of murder.
Ashour also reiterated the NSF's demands for the formation of a government of national salvation to deal with the current security and economic crises.
NSF spokesperson Ahmed al-Burai stated that the opposition bloc is preparing an economic plan "to rescue Egypt from the worsening economic situation."
The NSF meeting was also attended by opposition leaders Mohammed el-Baradei, George Ishak and Mohammed Sami.