A man who US authorities believe is the key figure behind an anti-Islam video that sparked violent protests in the Middle East, Africa and Asia is being questioned by probation officers in California.
Flanked by police, film-maker Nakoula Basseley Nakoula emerged from his house wearing a coat, hat, scarf and glasses, and was interviewed at the sheriff department station in his hometown of Cerritos.
A law enforcement official said authorities had connected self-described Coptic Christian Nakoula to a man using the pseudonym of Sam Bacile who claimed earlier to be writer and director of the film.
Sheriff's Deputy Don Walker said Nakoula, who has denied any involvement in the video, had travelled voluntarily in a police car and stressed he was not arrested or detained.
"He went to the Cerritos station to talk with probation officers. He's not under any arrest," he said.
Federal officials have said they were investigating the activities of 55-year-old Nakoula, who has been convicted of bank fraud.
If the probation department determines he has violated terms of his release, a judge could send him back to prison.
US officials have said authorities were not investigating the film project itself, and that even if it was inflammatory or led to violence, simply producing it cannot be considered a crime in the US, which has strong free speech laws.
American authorities have heavily criticised the 13-minute movie, called Innocence of Muslims. Filmed in California, and circulated on the internet, it depicts the Prophet Mohammed having sex, calling for massacres, and as a homosexual.
There have been protests in at least 12 countries and the demonstrations have spread to Sydney, Australia. About 200 protesters clashed with riot police at the US Consulate in the city.
US President Barack Obama ordered a review of security procedures at all US diplomatic facilities worldwide after protests targeted American embassies and consulates.
All non-essential staff at its embassies in Tunisia and Sudan are being evacuated.
The violence followed Tuesday night's storming of the US Consulate and a safe house in Benghazi, Libya, in which the US ambassador to the country, Chris Stevens, and three other American officials were killed.
Some 200 protesters gathered outside the US Embassy in London on Friday evening to express their fury over the film.
Widespread anger has seen violent scenes in the following countries:
Protesters stormed the US Embassy in the Tunisian capital Tunis, with plumes of black smoke pouring from near the compound.
Police fired tear gas at the crowds, who smashed windows in the building and torched trees.
At least two people were killed and 28 wounded during the clashes, according to Tunisian state TV.
Some 5,000 protesters attacked the British, German and US embassies in the Sudanese captial Khartoum.
Crowds broke into the German compound, tearing down the German sign and flags and flying a black Islamic flag above the building. They also smashed windows and started a fire in front of the main gate.
A separate protest group targeted the heavily fortified US Embassy on the outskirts of the city, climbing walls before they were expelled from the compound.
At least two people were reported to have been killed during the protest outside the US facility.
British Foreign Secretary William Hague said protesters caused minor damage to the British Embassy in Khartoum and that no workers were hurt during the incident.
Police guarding the US Embassy in Cairo clashed with groups of protesters near Tahrir Square.
TV pictures showed demonstrators throwing rocks and attacking a 15ft-high concrete wall built by police across the road to the US compound.
One protester was killed after he was shot with rubber bullets near the embassy. Several hundred have been involved with the protests.
Four soldiers from the multinational peacekeeping force in Sinai were injured after an attack on their main base near El Gorah.
Israeli media claimed a group of around 70 Bedouin salafists attacked the base in pick-up trucks, before armoured personnel carriers from the Egyptian army confronted them.
There were further clashes near the US Embassy in Sana'a, a day after demonstrators stormed the compound.
Reports said US Marines had been flown into the city's international airport on Thursday to bolster security around the facility.
At least one person died and 15 were injured during the demonstration on Thursday. Yemen's President Abd-Rabbu Mansour Hadi condemned the attack.
India and Bangladesh
Some 10,000 protesters burned US and Israeli flags as they attempted to march on the US Embassy in the Bangladeshi capital Dhaka.
They were stopped by hundreds of armed police using armoured personnel carriers.
Eighty six people have also been arrested as Muslim protesters attacked the US consulate in Chennai, India.
In the world's largest Muslim-majority nation, 250 riot police guarded the US Embassy in Jakarta as nearly 500 people staged a protest outside.
A KFC restaurant in the northern Lebanese city of Tripoli was set on fire by a crowd of protesters and one person was killed in violent clashes ahead of a three-day visit to the country by Pope Benedict.
Protesters set fire to an effigy of US President Barack Obama and demanded the death of the filmmaker they say insulted the Prophet Mohammed during clashes in Afghanistan.
Clerics in the Shinwari tribe called for a \$100,000 bounty on the head of the producer of the film during protests in Nangarhar province.
Nigerian troops opened fire with live rounds in the city of Jos as they attempted to disperse crowds of Muslim protesters.
Libya closed the air space above Benghazi - the scene of the fatal attack on the US consulate on Tuesday - after Islamists launched heavy anti-aircraft fire at US reconnaissance drones flying above the city.
US authorities also denied claims they had advance warning of the attack on the consulate.