Christians angered by the killing of four Christians in weekend sectarian violence have clashed with a mob throwing rocks and firebombs, killing one and turning Cairo's main Coptic cathedral into a battleground.
The clashes raised tempers in an already tense political atmosphere, as workers shut down the country's trains in a strike over wages and a dispute over the nation's chief prosecutor entered a new phase - all signs of two years of unending turmoil.
Reacting to Sunday's violence, the Muslim Brotherhood's political party blamed "dubious" attempts by unnamed parties to broaden instability in Egypt by igniting sectarian violence and spreading chaos.
A liberal opposition group, the Popular Current, said the clashes were symptomatic of the failure of the state to protect its citizens, calling on Islamist President Mohammed Morsi and his government to resign.
Mr Morsi said in a statement late on Sunday that he spoke to Pope Tawadros II by phone. He gave orders to authorities to guard the cathedral and citizens in the area, adding that protecting the lives of Muslims and Christians was a state responsibility. "I consider any attack on the cathedral as an attack on me, personally," he said, according to the statement from his office.
The clashes at the St. Mark Coptic Orthodox Cathedral began just after hundreds of angry Christians left the complex to stage an anti-government march following the funeral for the four Christians killed in sectarian clashes on Saturday. A mob, described by witnesses as residents of the area, pelted them with rocks and firebombs and fired birdshot, forcing them back inside the complex. Few police were present.
By the time police arrived in larger numbers, the church was the scene of clashes between those locked inside and the mob outside, as the two sides exchanged rocks and firebombs. Police fired tear gas, and gas canisters landing inside church grounds caused a panic among women and children. People outside the church cheered.
Tawadros was not in the cathedral, his headquarters, during the funeral and the violence that followed. In a statement carried by the state news agency, said he was "regretful" of the violence and called for calm.
"There was no security outside the church for such a large funeral," said Emad Thabet, a Coptic Christian who was among those locked up in the church for hours. "There is no such thing as Egyptians in Egypt. There are only Muslims and Christians," he said. Copts have complained for decades that the Christian minority suffers from discrimination."
Coptic Christians make up about 10% of Egypt's estimated 90 million people. Attacks against Christians have increased since the ouster two years ago of autocrat Hosni Mubarak.