Afghan officials have banned YouTube to prevent citizens accessing Innocence of Muslims, the US-made film that sparked protests across Cairo and Benghazi and led to the death of Chris Stevens, US ambassador to Libya.
The film, directed by elusive Jewish real estate developer Sam Bacile with the help of more than 100 Jewish donors, depicts the Prophet as an illegitimate son and feckless philander who approves of child sexual abuse.
"We have been told to shut down YouTube to the Afghan public until the video is taken down," Aimal Marjan, general director of information technology at the Ministry of Communications, said.
US pastor Terry Jones, whose threat to burn the Koran triggered riots in Afghanistan in 2010, said he had promoted Bacile's film.
As protests spread through the Muslim world, hyundreds of demonstrators led by a group called Sudanese Youth took to the streets near the American embassy in Khartoum.
"It has to do with this film," a US embassy official told AFP.
"They were asking for an immediate apology, removal of the YouTube video", and expressed their displeasure at Pastor Jones, the official said.
Egypt has arrested four people for breaching the US embassy over the film.
The US embassy in Algiers has warned Americans to avoid non-essential travel amid calls for protests.
Although the precise circumstances of ambassador Chris Stevens's death remain unclear, it is thought that the 52-year-old went to the US consulate in Benghazi a few hours after the initial attack on the compound.
Reports suggest that Stevens, Smith and their bodyguards were attacked in their car. The ambassador died of suffocation.