Following the sentencing of deposed Egyptian President Hosni Mubarak to life in prison on Saturday, tens of thousands of Egyptians flooded into Tahrir Square in Cairo, demanding the death penalty for the ailing former leader. Demonstrators blocked roads leading to the square, burned tires and hurled stones and bottles at security forces.

Similar protests went on in the Mediterranean port city of Alexandria and Suez on the Red Sea.

"Justice was not served. This is a sham," Ramadan Ahmed, whose son was killed on Jan. 28, the bloodiest day of last year's uprising, said ouside the courthouse.

Protesters chanted: "A farce, a farce, this trial is a farce," and "The people want execution of the murderer." While some called for Mubarak's execution, others feared the judge's ruling exposed weaknesses in the case that could let the ex-military strongman off on appeal.

The case against Mubarak, his sons and top aides was very limited in scope, focusing only on the uprising's first few days and two narrow corruption cases. It was never going to provide a full accountability of wrongdoing under Mubarak's three decades of authoritarian rule enforced by a brutal police force and a coterie of businessmen linked to the regime who amassed wealth while nearly half of Egypt's estimated 85 million people lived in poverty.

During the demonstration, protesters shouted slogans against the ruling military council, clashed with pro-Mubarak supporters and burned images of Mubarak and Ahmed Shafiq, who served as prime minister under Mubarak and made it to the runoff for Egypt's first democratic presidential elections scheduled for June 16-17.

Shafiq commented on the sentence on Saturday, saying, "Egypt's legal system meted out justice and proved that no one in Egypt is above the law. Every president who is elected must learn a historical lesson from this ruling."

Other presidential candidates denounced the sentence. Hamdeen Sabahi, a socialist and a champion of the poor who made a surprisingly strong showing in the first round of the elections but did not ultimately make it to the run-off, attended the demonstration at Tahrir Square and got a warm welcome from protesters.

"The ruling proves that Egypt's legal system is still infected with remnants of the former regime," Sabahi said as he was carried by supporters in the crowd.

Muslim Brotherhood presidential candidate Mohammed Morsi, who will face Shafiq in the run-off, not only condemned the sentence, but promised that if elected, he would demand a retrial for Mubarak.

"This criminal deserves the death penalty," Morsi told the Egyptian media. "With Allah's help, when we will be in power, we will replace the prosecutor and the judges and conduct a retrial to achieve a more appropriate sentence for Mubarak and his fellow criminals."

"Egypt and its revolutionary sons will continue their revolution. This revolution will not stop," he said.

Many in Egypt believe that Mubarak's sentence will have an influence on the run-off presidential elections, in favor of the Muslim Brotherhood's candidate. Others believe that demonstrations in Tahrir Square over the ruling will spiral out of control and that the ruling military council will cancel the run-off elections until stability is restored.