Clashes took place on Thursday outside the US embassy in Cairo between protesters and police, as President Mohamad Mursi rejected the attacks against the embassies.
Several people were injured as clashes took place between police and demonstrators in protest over a film mocking Islam.
Police used tear gas as they clashed with a stone- and bottle-throwing crowd protesting an offensive film to Islam and Prophet Mohammad (pbuh), witnesses and the interior ministry said.
The health ministry said 13 people were injured during sporadic clashes through the night outside the embassy, where on Tuesday thousands of protesters tore down the US flag and replaced it with an Islamic flag.
Meanwhile, President Mohamad Mursi slammed the attacks against Prophet Mohammad (pbuh) in the film which was produced by extremist Jews and Copts in the United States.
However he also voiced rejection to the attack on the US embassy in Cairo.
"We Egyptians reject any kind of assault or insult against our prophet. I condemn and oppose all who... insult our prophet," Mursi, on an official visit to Brussels, said in remarks broadcast by Egyptian state television.
"(But) it is our duty to protect our guests and visitors from abroad... I call on everyone to take that into consideration, not to violate Egyptian law... not to assault embassies," he added.