CAIRO - Nine people were killed in Cairo on Tuesday in clashes between opponents and Islamist supporters of Egypt's deposed President Mohamed Morsi, state-run media reported, keeping the most populous Arab nation in turmoil.

Members of the Muslim Brotherhood and supporters of ousted Egyptian President Mohamed Mursi (back) clash with anti-Mursi protesters, along Qasr Al Nil bridge, which leads to Tahrir Square, in Cairo July 22, 2013. [Photo/Agencies]

The violence broke out before dawn near a Brotherhood protest at Cairo University, where Morsi supporters have been camped out since the army removed the Islamist politician from power on July 3 following protests against his rule.    

The Brotherhood described it as an attack on peaceful protesters and blamed the killing on thugs backed by the Interior Ministry - an accusation a security official denied.

Police sources said hundreds of Morsi supporters clashed with local residents, street vendors and others near the sit-in. They said gunshots were fired and stones were thrown.

With the Brotherhood vowing to stay in the streets, the bloodshed was a fresh example of the instability facing Egypt as

the newly installed interim government moves along an army-backed roadmap towards elections in about six months.

"The longer this standoff continues, the more hardened the positions become, and the more likelihood there is for violence, and oppression," said Yasser el-Shimy, Egypt analyst with the International Crisis Group.

"It needs an urgent political deal or compromise and unfortunately we are not seeing any signs of that."    

The state-run Al-Ahram newspaper quoted a health ministry official as saying nine people had been killed and 33 wounded in the Cairo University clashes, while two wounded in fighting on Monday had died, bringing to 14 the number of deaths in violence between rival protesters in Egypt in the last two days.

At least 15 burned-out cars lay abandoned around the university area where the clashes took place. Splattered blood and broken glass disfigured the pavements near the shopping area where a traffic police station was set on fire.

Brotherhood members with sticks guarded the entrance to the protest site after the clashes calmed, while residents stopped cars on the road to Cairo University to check for weapons.

About 100 people have died in violence since the army deposed Morsi and replaced him with an interim administration led by the Adli Mansour, the head of the constitutional court. The Brotherhood accuses the army of orchestrating a coup.

It said on its website that seven "martyears" had been killed overnight in two separate attacks on Morsi supporters, one at Cairo University and another during a march near a bigger round-the-clock sit-in in the north of the city.

Egypt's general prosecutor ordered 22 pro-Morsi protesters be detained for 15 days while they are investigated over accusations they attacked the ousted president's opponents in central Cairo on Monday, the state news agency said.

They are also accused of carrying unlicensed fire arms and ammunition, the report said.