UN human rights chief Navi Pillay said on Friday that Egypt would experience the kind of change that has swept Tunisia in the wake of a popular revolt that toppled the country's president in January.
"Change is coming to Egypt, as it came to Tunisia, but the violence and bloodshed must stop now," the UN High Commissioner for Human Rights told journalists.
Pillay was speaking as Egyptian protesters massed on Friday for sweeping "departure day" demonstrations to force President Hosni Mubarak to quit.
Zine El Abidine Ben Ali, president of Tunisia for 23 years, fled to Saudi Arabia three weeks ago after an uprising which has since inspired opposition movements throughout the Arab world.
Pillay had earlier called for an investigation into an escalation in violence in Egypt this week following violent clashes between pro and anti Mubarak supporters.