Eyewitnesses said that a section of the protesters had remained for the all-night vigil.
The presidential secretariat which was occupied by the protesters from July 9 till Friday last is re-opened and the staff reported to work on Monday, officials said.
Defeated joint opposition candidate Gen Sarath Fonseka rejected the Sri Lankan government's allegations on Thursday that he had attempted to assassinate President Mahinda Rajapakasa, terming it as "trumped up charges" to arrest him.
Police said most of the victims were burnt to death as they were unable to get out of the bus, which caught fire at Induruwa along the Galle Road this morning.