At least one person was killed Friday in front of the presidential palace as thousands of people were on the streets in Cairo and other cities calling for a new government.
Qandil spoke in a prerecorded address broadcast to the country hours after another day of widespread protests, Ahram Online reported.
"The government, as well as all political forces, has failed to accommodate the demands of the youth," he said.
Some people threw bottles at the prime minister's motorcade Saturday when he visited Tahrir Square in Cairo -- the center of protests that brought down President Hosni Mubarak in 2011, and of more recent demonstrations against President Mohamed Morsi.
Qandil said the opposition should condemn violence and focus on upcoming elections.
"Whenever we face a problem during the transitional phase, political forces demand sacking the government and dissolving the parliament," he said. "They ask that we knock down the institutions which we built ourselves."
Yasser Ali, a Morsi spokesman, said Saturday the government has begun an investigation into attacks on the presidential palace, al-Masry al-Youm reported.