CAIRO (AFP) - Three women died in clashes between loyalists and opponents of Egypt's ousted Islamist president Mohamed Mursi, medics said on Saturday, despite warnings by the military that it would crackdown on violent protests.

"Three people were killed and seven others wounded by birdshot and stabbing attacks during clashes between Mursi supporters and his opponents," Mr Adel Said, a hospital official in the Nile Delta city of Mansura, told AFP. The three killed on Friday were all women, he added.

A pro-Mursi protester injured in the clashes, also speaking by phone, said thousands of loyalists were marching through the city's narrow streets when "thugs" attacked them with guns, knives and rocks.

Tensions are running high in Egypt more than two weeks after the army ousted the country's first freely elected president following massive protests calling for him to go. Rival protests were staged in several cities on Friday, with tens of thousands rallying in Cairo to demand the Islamist leader's reinstatement. Before Friday's demonstrations, the army warned that it would decisively confront any violent protesters.

Mr Mursi's army-installed successor Adly Mansour vowed to fight for stability against opponents he accused of wanting to plunge the crisis-hit country "into the unknown".

Several thousand supporters of Mr Mursi's overthrow by the military descended on Cairo's Tahrir Square on Friday evening, setting off fireworks and chanting pro-army slogans. Earlier, a vast crowd gathered at the Rabaa al-Adawiya mosque in the capital, where Mursi loyalists have camped out since the military overthrew him on July 3. About 10,000 protesters then set off in the direction of an elite military compound, the scene of the deadliest violence since Mr Mursi's overthrow, carrying pictures of the deposed president and chanting slogans. But they were blocked by soldiers and armoured vehicles.

"I believe Mursi will return as president, God willing. The people will win in the end," said protester Mohammed, a 45-year-old veterinarian.

Smaller rallies took place elsewhere in Cairo and Egypt's second city Alexandria after the Muslim Brotherhood had called for a day of protests dubbed "Breaking the Coup".

Mr Mursi has been held in custody since his ouster, and other senior Brotherhood leaders have also been detained, prompting international concerns.