The US has started investigating the attack on its embassy in Benghazi and the deaths of US Ambassador to Libya Christopher Stevens and four other staff members. To find out whether it was a planned attack, or a spontaneous reaction against an alleged anti-Islam film.

Overnight there have been fresh protests and clashes in Egypt, who also believe that the film insults their Prophet Muhammad. Protesters scaled the walls of the U.S. embassy in Cairo and replaced an American flag with a black flag. Riot police drove the estimated 2000 crowds away from the embassy, but protests continued late into the night. Some protestors threw stones at the police, who responded by firing tear gas canisters into the crowd.

This resident explained that the film has inflamed Egyptian Muslims in Egypt and they will react violently.

"We have to have an opportunity just to stop this film. Stopping the film is our hope, is our relationship with Americans. Americans want to say something bad about Prophet Mohammad. Prophet Mohammad, I am speaking in English now to them. So don't make our people angry because they will kill, they will fight, they will do such a situation."

While over in the US a candlelight vigil has been held outside the White house for Ambassador Stevens and the victims of the bomb attack. President Obama said the US vowed to bring the Benghazi killers to justice. Calling the attack "outrageous and shocking" but insisted it would not threaten relations with Libya's new elected government.

Written and Presented by Ann salter