The violence erupted when over 500 Brotherhood supporters staged a march in Giza, which is part of greater Cairo, after morning prayers to mark the end of the holy month of Ramadan and the start of the major Muslim holiday, Eid al-Fitr.

At least six people were killed.

Smaller clashes quickly escalated into deadly violence with the use of live ammunition and shotguns according to an official, who spoke on condition of anonymity in line with Egyptian regulations.#

Police arrests in several cities

Later, Egyptian state news agency MENA reported that police had regained control of the area, which is located near the main road that leads to the famed Giza pyramids. The MENA news agency added that police had also arrested 15 Muslim Brotherhood supporters.

Meanwhile, the state-run al-Ahram newspaper reported that a homemade bomb had also gone off in the same area without resulting in any casualties, while two other bombs had successfully been diffused. In Alexandria, Egypt's second biggest city, police dispersed several pro-Morsi marches and arrested 20 protesters for holding anti-government placards.

Pro-Brotherhood websites accused police of targeting what they called "peaceful protesters."

Muslim Brotherhood denies use of violence

Political violence has increased in Egypt, two years after Islamist President Mohammed Morsi was ousted by the military, following mass protests against his rule. After Morsi's ouster, his successor and current President Abdel-Fattah el-Sissi launched a sweeping crackdown on dissent that has seen hundreds killed.

Egyptian authorities blame many attacks on Morsi's Muslim Brotherhood group, which denies using violence. But Brotherhood ranks have become divided recently on whether to use force to confront the government in response to the nearly two-year-old crackdown against them.

A death sentence against ex-President Morsi was upheld in June.

ss/kms (AP, dpa)