Egypt's military ruler, Field Marshal Mohamed Hussein Tantawi, has rejected the resignation of the country's deputy prime minister in the wake of violent clashes between security forces and Coptic Christians that left 26 people dead.

Hazem El-Beblawi submitted his intention to leave the Cabinet on Tuesday, citing a “severe breach of the security and safety of society” after Sunday's violence. Beblawi also serves as finance minister, and is currently in talks with Saudi Arabia and the United Arab Emirates for $5 billion in loans.

Egyptian media quote Tantawi as saying Egypt's current circumstances do not allow for the resignation to be accepted.

Sunday's unrest began after more than 1,000 Christians marched to the state television building in Cairo to protest a recent attack by Islamist radicals on a Coptic church in the country's south.

Egypt's ruling military council has ordered the government to investigate the violence.

Speaking by telephone Tuesday with Foreign Minister Mohamed Kamel Amr, U.S. Secretary of State Hillary Clinton said the United States supports the investigation, and called on the government to ensure the rights of religious freedom and peaceful assembly. She said the U.S. is deeply concerned about the violence and urged the government to end military trials for civilians.

Videos of military armored vehicles plowing through Christian protesters and images of their flattened bodies are fueling rage against Egypt's ruling army generals, even beyond the country's Coptic community. Activists accuse the military of instigating sectarian hatred as a way to end protests and halt criticism.

Anger also has focused on Egypt's state television, blamed for inciting attacks on Christians. During the clashes, a television presenter urged “honest Egyptians” to go out and protect the army, saying Coptic protesters were attacking soldiers “with stones and Molotov cocktails.”

Soon, bands of armed Muslim men arrived at the protest and clashed with stone-throwing Christians.

Also Tuesday, Copts began three days of mourning for the protesters killed during the street violence. Church leaders urged followers to fast and pray during the mourning period.

Coptic Christians make up about 10 percent of Egypt's roughly 80 million people. Many complain that Egypt's new leadership has been too lenient on Islamists they blame for a series of anti-Christian attacks since a popular uprising forced the resignation of President Hosni Mubarak in February.

The Coptic church issued a statement saying the minority community has suffered repeated problems and the perpetrators have gone unpunished.