Clashes on Friday between loyalists and opponents of Egypt's ousted Islamist president Mohamed Morsi left three women dead in the Nile Delta city of Mansura, medical sources said.
"Three people were killed and seven others wounded by birdshot and stabbing attacks during clashes between Morsi supporters and his opponents," Adel Said, a hospital official in Mansura, told AFP.
He gave the names of the three people killed, all women.
Another health official in Mansura, Abdel Wahab Suleiman, confirmed the death toll, saying three women were killed by gunshot and ten people wounded, one of whom was in a critical condition.
A pro-Morsi 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 different 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.
"Whoever resorts to violence in Friday's protests will endanger his life, and will be treated with utmost decisiveness, within legal bounds," it said.
Morsi'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".
"We will fight the battle for security to the end. We will preserve the revolution," he said in a speech broadcast by state television on Thursday.