Egyptian officials say the death toll from clashes between security forces and protesters on the third anniversary of the country's 2011 uprising has risen to 49.

The Health Ministry, quoted by the official MENA news agency on Sunday, said another 247 were wounded. The agency quotes the Interior Ministry as saying 1,079 were arrested.

Saturday marked the anniversary of the start of the 2011 uprising that forced longtime autocrat Hosni Mubarak to step down.

It was marked by rival rallies of those supporting the military-backed government and supporters of Mubarak's successor, Islamist President Mohammed Morsi, who was removed from office in July following mass protests against him.

Security forces crushed demonstrations by rival Islamists and some secular activists. Pro-army civilians joined the police in some of the clashes.

Meanwhile in Tahrir Square, birthplace of the 2011 uprising, giant crowds at government-backed rallies demanded army chief Gen. Abdel-Fattah el-Sissi run for president.

Meanwhile, four Egyptian soldiers were killed and nine wounded when gunmen attacked a military bus on Sunday that was travelling in the Sinai Peninsula, security sources said.

Sinai-based militants have stepped up violence against the state since Morsi's ouster, and the attacks have become more brazen in recent months, spreading to Cairo and other cities.

