Seven people were killed and more than 260 wounded when supporters of Mohamed Mursi clashed with the deposed president's opponents and security forces through the night as violence returned to Egypt's streets.

Two people were killed at a bridge in central Cairo where police and anti-Mursi locals clashed with some of his supporters who were blocking a route across the River Nile. Another five were killed in the Cairo district of Giza, said the head of emergency services, Mohamed Sultan.

The street battles, which raged into the early hours of Tuesday morning, were the bloodiest since more than 50 Mursi supporters were killed a week ago. The violence overshadows attempts by the authorities to press on with a transition to full civilian rule by naming a new cabinet after the army pushed Mursi, an Islamist, out of power on July 3.

"We were crouched on the ground, we were praying. Suddenly there was shouting. We looked up and the police were on the bridge firing tear gas down on us," said pro-Mursi protester Adel Asman, 42, who was coughing, spitting and pouring Pepsi on his eyes to ease the effect of tear gas.

By sunrise calm had returned. The unrest is more localised than in the days after Mursi was toppled when 92 people died, but Egyptians still worry about the authorities' ability to restore order nearly two weeks after Mursi's removal.

"I've had enough of this chaos," said Ashraf Mohamed, who watched the clashes from a distance. "Egypt is just rubbish."

Military helicopters hovered overhead and police vans were brought in to quell the trouble, but when that didn't work, dozens of riot police moved in. Medics treated men with deep gashes to their eyes and faces nearby.

Millions of Egyptians rallied for Mursi's resignation on June 30. The military said it deposed him to fulfil the wish of the people. Mursi's Muslim Brotherhood said it was a coup.

"It's the army against the people, these are our soldiers, we have no weapons," said Alaa el-Din, a 34-year-old computer engineer, clutching a laptop during the melee.

"The army is killing our brothers, you are meant to defend me and you are attacking me. The army turned against the Egyptian people."

Egypt has become increasingly polarised by the crisis, but one thing the two sides share is a deep mistrust of the United States and its perceived role in the unrest. – Reuters