Christian protesters in Cairo threw rocks and gasoline bombs Sunday, as a march to protest an attack on a church spiraled out of control, leaving 19 dead. The clashes represented "some of the most violent scenes since an uprising ousted ex-President Hosni Mubarak in February," Reuters reported.

More than four vehicles were set ablaze and TV footage showed protesters breaking windows of parked cars and army personnel carriers driving full speed toward crowds of protesters.

Gun shots were heard and witnesses said crowds of protesters carried bodies as tear gas filled the air. It was unclear who was shooting.

"We were marching peacefully," Talaat Youssef, 23-year old Christian trader told Reuters at the scene.

"When we got to the state television building, the army started firing live ammunition," he said, adding army vehicles ran over protesters, killing five. His account could not be immediately confirmed.

"The army is supposed to be protecting us," Youssef said.

The violence comes as Egypt's military ruling council has tried to tamp down religious rhetoric in other ways, notably banning the use of religious symbols in upcoming elections. That may trigger a change in the traditional electoral slogan used by candidates of the Muslim Brotherhood, the fundamentalist group.

Many liberal politicians and Egyptians have been worried by the rising influence of the Brotherhood since the uprising. The group has sought to quell concerns by saying it wants a pluralist democracy and did not want to impose Islamic law.

"Electoral campaigns based on the use of religious slogans or on racial or gender segregation are banned," a military council decree issued late Saturday said, adding violators could face three months in jail and be fined.

The election committee earlier said the Brotherhood's Freedom and Justice party could not use the slogan, prompting some members to insist it should be allowed. But Brotherhood officials took a softer line after the army decree.

"The slogan is a way of life for us but it isn't necessarily an electoral slogan," Mohamed el-Beltagy, a senior figure in the Freedom and Justice party, told Reuters after the decree.

Voting begins on Nov. 28.