The United States has ordered non-essential diplomatic staff and family members to leave its embassies in Tunisia and Sudan following violent protests over a film that mocks Islam.
Sudan has rejected a request from the United States to allow a unit of American Marines onto its territory to bolster security at the US embassy in Khartoum.
Protesters on Friday forced their way into the compound of the US embassy on the outskirts of the Sudanese capital and attacked the embassies of Germany and Britain.
However Sudan's foreign minister told the state news agency his country is capable of protecting all diplomatic missions itself.
A US official said the Marines had already set off for Khartoum but had been called back pending further discussions with Sudan.
The film depicts the Prophet Mohammad as a womaniser and charlatan and Muslim outrage has led to crowds assaulting US diplomatic missions in a number of Arab countries.
In a statement, the US State Department also urged US citizens in Tunisia to make their way out of the country and advised Americans to avoid travel to some regions of Sudan.
Australia police vow to crack down on 'extremist criminals'
In Australia, police have vowed to crack down on what they are calling 'extremist criminals' in the wake of a violent demonstration in Sydney in which six officers were injured.
The ABC reports six people have been charged after hundreds of Muslims descended on central Sydney to voice their anger over the anti-Islamic film.
New South Wales Police Commissioner Andrew Scipione says he was shocked by Saturday's violent scenes where officers were reportedly pelted with glass bottles and police cars damaged.
One of the six protesters charged over the violent protest was denied bail on Sunday when he appeared via video link in the Parramatta Local Court.
His co-accused are on bail to appear in court next month.