Christian protesters disregarded a call by their faith's top Egyptian leader to end a weeklong sit-in in front of a government building on the Nile, remaining in place Sunday, a day after a mob attacked them and their supporters, injuring 78.

The sit-in aimed to draw attention to the plight of Christians, who have been the target of several attacks by Muslim fundamentalists in the weeks since Egyptian President Hosni Mubarak was forced from office by a popular uprising.

The head of Egypt's Coptic Orthodox Church, Pope Shenouda III, said in a statement that outsiders have infiltrated the sit-in of largely Christian demonstrators, making the situation even more explosive.

"This has exceeded the mere expression of opinion," the statement said, "harming Egypt's reputation and your reputation."

He warned that Egypt's military rulers and interim civilian government were losing patience with the protesters and that they "will be the losers if this sit-in continues."

By late Sunday, however, the protesters — many of whom have been camping out on the riverbank in front of the state TV building — showed no sign of leaving, even gaining new strength.

Girgis Atef, a 24-year old protest organizer, said they won't leave until their demands are met, most urgently the prosecution of church assailants and the release of Christian protesters detained and sentenced in previous protests following violence against Christians.

"The pope is our father and the leader of the Church. He loves and is hurt by what happened to us," Atef said. "No father would be unjust to his children and be a tool to pressure them so they can forgo their rights."

Christians, who make up about 10 percent of Egypt's population, have felt increasingly insecure since 18 days of street protests brought down Mubarak, who led the country for nearly 30 years until he was forced to resign on Feb. 11.

The Christians, many of whom are Coptic, have complained that the interim government and security forces have failed to protect them and have allowed extremist Islamic groups to attack with impunity.

Earlier this month, mobs of Muslims, apparently urged on by the ultraconservative Salafi sect of Islam, stormed the Virgin Mary Church in the Cairo neighborhood of Imbaba and set it ablaze. The attack was sparked by a rumor that a Christian woman planned to marry a Muslim, which some religious purists consider to be forbidden.

A short distance away, the mob tried to storm the Mar Mina Church, but were held back by Christians who formed a human shield around the church and fought for hours.

Fifteen people were killed and more than 200 were injured in the melees. No trial date has been set for those arrested in the attacks.

Several weeks before the attacks on the churches, Egyptians led by hard-line Islamists repeatedly rallied and marched to protest the appointment of a Coptic Christian governor in the southern Egyptian province of Qena.

Violence against the sit-in in Cairo erupted late Saturday night, when a mob of more than 100 people lobbed rocks and firebombs and charged dozens of people sleeping in the area. Some 15 vehicles were also set on fire and damaged.

Armored military vehicles later blocked cars and pedestrians from going to the state TV building. More than 50 people were arrested and were being interrogated, security officials said.

Some of the Christian protesters fled, but others said they would continue their sit-in.

Atef, who was injured in the melee, blamed the attack on thugs and complained that it took three hours for Egyptian security forces to respond. The violence didn't end until early Sunday morning.

"What is behind this military reluctance? Is it semi-collaboration?" he asked.

Medhat Kalada, head of the Geneva-based United Copts organization, criticized the sit-in and said that attention should be directed to political process, not street protests.

"Egypt is passing through a critical phase, and we should pay attention to the political process," said Kalada who was part of a Christian delegation that met recently with Egypt's military rulers and said that the group received assurances that Christian needs would be met.

"I understand that the youth are angry, but we need wisdom now, not anger," he said.