Egypt's first Islamist president, Mohamed Mursi, was sworn in on Saturday, propelling his Muslim Brotherhood into power after 84 years of struggle, although the military remains determined to call the shots.

Immediately after swearing his oath, he said a civil, national, constitutional and modern state was "born today".

The bearded US-trained engineer is Egypt's first non-military president since army officers toppled the king in 1952. For the Brotherhood, banned and repressed under ousted leader Hosni Mubarak, it marks a dramatic reversal of fortunes.

"I swear by Almighty God that I will sincerely protect the republican system and that I will respect the constitution and the rule of law," Mursi told judges at the Supreme Constitutional Court, repeating vows he had uttered the day before to supporters thronging Cairo's Tahrir Square.

"I will look after the interests of the people and protect the independence of the nation and safety of its territory."

Mursi, 60, took his oath in the constitutional court, instead of parliament as is usual, because the court had dissolved the Islamist-led lower house earlier this month amid a raft of measures to ensure enduring military influence.

Mursi had shown his distaste for this by his symbolic oath-taking in Tahrir, crucible of the anti-Mubarak revolt, where he said the people were the only source of power, in a dig at the generals who see themselves as the state's ultimate arbiters.

After the oath-taking, Mursi went to Cairo University to speak at the podium used by US President Barack Obama to reach out to the Islamic world in 2009, early in his term.

An honor guard, artillery salute and the national anthem greeted Mursi on his arrival at the university, where "No SCAF (Supreme Council of the Armed Forces)" was scrawled on a wall.

The audience included women in full Islamic face veils or headscarves, some carrying portraits of dead protesters. There were Christian priests, Muslim clerics and men in suits or traditional robes and head-dresses, some with beards.

The arrival of Egypt's military chief, Field Marshal Hussein Tantawi, provoked extraordinary scenes, with chants of "Down with military rule" countered by applause for Tantawi.

The presiding official then led the crowd in the hall in chants of "The army and people are one hand", although some shouted "Allahu akbar (God is greatest)".

Mursi, in a grey suit and red tie, started his own speech with the same words, saying "God is greatest, above everyone".

Tantawi's SCAF has led Egypt's chaotic and sometimes bloody transition since Mubarak's overthrow, holding elections, but ruling by decree with arbitrary and often contradictory decisions, even as the economy shrinks with millions jobless.

A few dozen pro-military demonstrators blocked a highway in Cairo's Nasser City on Saturday, holding banners reading: "Yes to the constitutional declaration" - referring to an army decree on June 17, the last day of the presidential run-off vote.

The decree clipped presidential powers, denying the head of state his role as supreme commander of the armed forces with the right to decide on war and peace. It also gave the army council legislative powers until a new parliament is elected, as well as veto rights over the writing of a new constitution.

The constitutional court building is next to the plush military hospital where Mubarak was transferred last week from the prison where he had begun a life term for failing to stop police killings of people protesting against his 30-year rule.-Reuters