Supporters of Egyptian President Mohamed Morsi scuffled with opponents in Cairo's Tahrir Square on Friday in the worst violence since Egypt's new Islamist leader took office this year.

Morsi's Muslim Brotherhood movement and a coalition of secular leaning groups were holding separate rallies when people from each side began throwing stones at one another. The health ministry said at least 12 people were wounded.

The violence came after Mr. Morsi removed his prosecutor general from office on Thursday after a court acquitted loyalists of ousted President Hosni Mubarak of organizing a brutal attack on protesters last year.

Nancy Okail, director of Freedom House's Egypt office in Cairo, tells VOA the acquittals are causing “obvious dismay” for Mr. Morsi. But she says that does not give the president the legal authority to remove his prosecutor general.

“The president does not have the right to dismiss the public prosecutor or any legislative authority unless their is a crime or there is a low case against him. The public prosecutor can resign, but he cannot be dismissed.”

Egyptian state television said Mr. Morsi skirted the legal process by naming Prosecutor General Abdel Maguid Mahmoud as the country's ambassador to the Vatican.

The announcement follows activists blaming Mahmoud of presenting weak evidence that resulted in the acquittals of 24 Mubarak loyalists.

They had faced charges for organizing a notorious camel-borne assault on protesters during last year's popular uprising.

In a speech in the coastal city of Alexandria on Friday, Mr. Morsi promised to bring to justice the officials accused of organizing the killing protesters.

“We will never ignore those who committed crimes against the nation and corrupted it,” he said, according to the official MENA news agency.