Libyan authorities have arrested four people in connection with the attack on the US consulate in Benghazi which killed US ambassador Chris Stevens and three other staff members.

With the Islamic world still in uproar over the Islamopohobic film Innocence of Muslims, which was produced in America, Libyan authorities are concerned about the potential for further violence against US buildings over the coming days.

Deputy Interior Wanis Sharif, speaking to Reuters, confirmed that "four men are in custody and we are interrogating them because they are suspected of helping instigate the events at the US consulate". However, he gave no further details.

Elsewhere, protests are continuing to rage against the release of the film. More than 200 people have been injured in Cairo as protesters tried to storm the US embassy, which first came under attack on 11 September.

Egypt's Muslim Brotherhood has demanded a 'million-man march' through the capital following Friday prayers, although the country's ruling party is adamant that this should be a peaceful event.

Further demonstrations have taken place outside American missions in Morocco, Sudan, Tunisia and Bangladesh. Nearly a dozen Islamic countries are facing protests in all.

Leaders across the world are deeply concerned over the situation. Russian President Vladimir Putin said the Middle East is on the brink of plunging into chaos. "We are afraid that the region may descend into chaos, which is essentially what is happening already," he said.

In an attempt to quell the violence, the US government continues to denounce the film, saying it is a privately-produced film and Washington has nothing to do with it.

"Let me state very clearly -- and I hope it is obvious -- that the United States government had absolutely nothing to do with this video. To us, to me, personally, this video is disgusting and reprehensible. It appears to have a deeply cynical purpose, to denigrate a great religion and to provoke rage," says US Secretary of State Hillary Clinton.

US President Barack Obama has urged governments in the affected countries to take effective measures to ensure the safety of American citizens.

"President Obama expressed appreciation for the co-operation we have received from the Yemeni government and underscored the importance of working together to ensure the security of US personnel," said a White House statement.