Egypt to have presidential elections first NEW: Interim president says he's amending road map laid down last summer NEW: "We are adamant -- state and people -- to eradicate terrorism," president says Armed men attack bus carrying soldiers in Sinai At least 49 people were killed in violence marking third anniversary of 2011 revolution (CNN) -- Egypt will elect a president before voting on a parliament, interim President Adly Mansour said Sunday, amending a road map laid down last summer. Parliamentary elections were supposed to be held first under a timetable agreed to after Egypt's army deposed Islamist President Mohamed Morsy in July following mass protests against his rule. Voters in the Arab world's most populous nation this month overwhelmingly approved a new constitution with 98.1% in favor, the Electoral Commission said. "I had previously held a series of sessions for dialogue with some of the major political stakeholders and representatives of the different political groups which indicated a majority in favor of holding presidential elections first," Mansour said in a televised address. In this light, I have taken the decision to amend the road map for the future, so that presidential elections are held first, and are followed by parliamentary elections. Mansour did not give exact dates for the elections. Egypt's army chief Gen. Abdel Fattah el-Sisi has said he would run for president if the Egyptian people wanted him to, state media reported recently. The country has seen months of political turmoil since its first democratically elected president, Morsy of the Muslim Brotherhood, was deposed by the military and an interim, military-backed government was installed in his place. Supporters of the now-banned Muslim Brotherhood boycotted the constitution referendum in response to a continuing government crackdown. Deadly blasts in Cairo condemned Mansour also condemned last week's "terrorist attacks" -- deadly blasts that rocked the capital, Cairo. "We are adamant -- state and people -- to eradicate terrorism and implement the 'road map for the future,'" he said. A terrorist group claimed responsibility Saturday for four blasts that killed at least six people in and around the city on Friday. At least 49 dead as throngs commemorate revolution The blast struck a key symbol of authority in the country. And later, a fourth explosion outside a movie theater in Giza, near Cairo, killed one person and injured seven others, state television said. Mansour was speaking after at least 49 people were killed and 247 wounded in violence Saturday marking the third anniversary of the January 25 revolution that brought down longtime dictator Hosni Mubarak, Egyptian state media said. Dozens more people were wounded in clashes throughout the country on Saturday between anti-government protesters and security forces. The casualty figures came from the Ministry of Health, state media said. Activists behind bars on uprising's anniversary Sinai attack kills 3 soldiers On Sunday, three Egyptian soldiers were killed and 11 others wounded when unknown armed men attacked their bus in the Sinai, a military official told Egyptian state news agency MENA. The attack came a day after five crew members were killed on board a military helicopter that crashed in the Sinai during operations targeting militants, according to state news agency EgyNews. Since Morsy's ouster, Egypt's political scene has become extremely polarized between the former president's Islamist supporters and those who back the military. Morsy's supporters have held held near-daily protests since his ouster, demanding he be reinstated. The protests have often devolved into violence. Mansour also said he appealed to prosecutors to review the cases of detainees held without charges from protests, including university students, to ensure that those held for no reason are released. CNN's Mohammed Tawfeeq contributed to this report.