The clashes erupted when pro-Morsi supporters had tried to march to the US embassy through the Tahrir Square, where opponents are camping.
Security forces fired tear gas canisters at the pro-Morsi protestors, forcing them to back away from the embassy building.
A security source said a 21-year-old man died after being shot in the chest.
It is not yet known whether he was a pro-Morsi loyalist or opponent.
Morsi, Egypt's first democratically elected president, was ousted by the army on July 3 following mass protests against his regime.
The military also suspended the constitution and installed Adly Mansour, the head of the constitutional court, as interim president.
Morsi supporters have since been organizing mass demonstrations and sit-ins nationwide to defend his democratic legitimacy and demand his reinstatement.
The National Alliance for the Defense of Legitimacy, a coalition of largely Islamist parties and groups including the Muslim Brotherhood, is organizing mass protests on Monday in support of the ousted president.
Supporters and opponents of ousted president Mohamed Morsi have traded blame for violent clashes near Tahrir Square that killed at least one person and injured 23 others.
The violence erupted after a pro-Morsi rally had tried to march on the US embassy through Tahrir Square, were opponents have been camping out.
In a Monday statement, Khalid Younis, the leader of under-construction Tahrir Youth Party, accused Muslim Brotherhood members of using live ammunition while attempting to storm the square.
He said police forces had used tear gas canisters to disperse the attackers while army troops separated between the two camps.
He insisted that three people were killed and between 150 to 200 others injured in the attempt by pro-Morsi supporters to storm the square.
Liberal writer Alaa Aswani accused the Muslim Brotherhood supporters of "thuggery".
"Why have you gone to Tahrir to assault the protestors," he asked in a post on his Twitter account.
But Muslim Brotherhood leader Azab Mostafa denied that the pro-Morsi supporters had sought to storm the Tahrir Square.
"This is an unfounded accusation," Mostafa, a member of the Brotherhood's Freedom and Justice Party, told Anadolu Agency, insisting that pro-Morsi supporters had not sought to attack the square.
"What happened was that thugs in the square had got out to attack our peaceful march under the eye of security forces," he said.
He lamented that pro-Morsi protests are being targeted by thugs supported by security forces.
Abdel-Rahman Al-Bar, a member of the MB Guidance office, also denied that Morsi followers had attacked the square.
He, however, insisted that protestors will continue their peaceful protests until legitimacy is restored.
Morsi, Egypt's first democratically elected president, was ousted by the army on July 3 following mass protests against his regime.
The military also suspended the constitution and installed Adly Mansour, the head of the constitutional court, as interim president.
Morsi supporters have since been organizing mass demonstrations and sit-ins nationwide to defend his democratic legitimacy and demand his reinstatement.
The National Alliance for the Defense of Legitimacy, a coalition of largely Islamist parties and groups including the Muslim Brotherhood, is organizing mass protests on Monday in support of the ousted president.
englishnews@aa.com.tr
