Violence increased in Cairo’s Tahrir Square Thursday following clashes between anti- and pro-Mubarak activists on Wednesday. At least five anti-government demonstrators were shot dead and over 800 injured in the square during the escalated fighting on Thursday. As the army intervened between the two sides, Egypt’s Prime Minister Ahmed Shafiq and Vice President Omar Suleiman both vowed to find those responsible for the violence. "I offer my apology for everything that happened yesterday because it's neither logical nor rational," Shafiq said Thursday. Suleiman also said that neither President Hosni Mubarak nor his son Gamal will run in the coming elections. Observers say the pro-Mubarak push Wednesday, in which Mubarak supporters rode through protesters in Tahrir Square on horseback wielding whips and threw Molotov cocktails, was likely orchestrated by the government. Back in Washington, President Obama said during a prayer breakfast: "We pray that the violence in Egypt will end, and that the rights and aspirations of the Egyptian people will be realized, and that a better day will dawn over Egypt and throughout the world."