The Freedom and Justice Party (FJP) accused the liberal Constitution Party of kidnapping one of its members in Alexandria, northern Egypt, and physically assaulting him.
The FJP, the Muslim Brotherhood's political wing, published a statement Saturday on its Facebook page saying that member Ahmed Saeed was kidnapped "in retaliation after citizens of Sidi Bishr [Alexandria] district turned in [a Constitution Party member] to the police to stop him from storming the [FJP] office."
According to the statement, Saeed is currently free. However, the party describes the alleged kidnapping as a "dangerous shift" in political practice.
The FJP held the Constitution Party responsible for the alleged incident and warned that it can control its members, "who are fed up with attacks on their offices and colleagues, but cannot control the anger of [Saeed's] relatives and friends."
The statement also said the FJP will not let go of their members' rights and will seek legal action "to prevent the country from plummeting into chaos."
Clashes broke out in Alexandria between pro and anti-Brotherhood groups earlier Friday in the coastal city of Alexandria, following marches demanding the removal of the Morsi-appointed prosecutor-general.
Morsi hails from the Muslim Brotherhood and was fielded for president by the FJP last year. He has been in power for nine months.
Former prosecutor-general Abdel-Meguid Mahmoud was dismissed by Morsi's constitutional declaration in November 2012 and Talaat Abdullah was appointed to replace him.
Many argue that Morsi's decision was unconstitutional.