Afghanistan on Wednesday strongly condemned as "inhuman and insulting" a film deemed offensive to Islam as it braced for possible protests after an anti-US riot in Libya killed the American ambassador and three other diplomats.
President Barack Obama ordered increased security at US diplomatic missions around the world and condemned Tuesday's deadly assault in Benghazi, in eastern Libya, that coincided with the anniversary of the September 11 attacks in the United States.
Made by an Israeli-American, the film describes Islam as a "cancer" and depicts the Prophet Mohammed sleeping with women, the Wall Street Journal reported.
The film has been promoted by controversial US pastor Terry Jones, who has drawn protests for burning the Koran and vehemently opposing the construction of a mosque near Ground Zero in New York.
The Afghan government released a statement strongly denouncing "the desecrating" film, calling for efforts to prevent the release of the insulting film and denouncing the producer and the US pastor.
It called the film an insult to the values of 1.5 billion Muslims across the world, and said it had "badly impacted the peaceful coexistence between human beings".
"This heinous act has created outrage and anxiety for all peace-loving humans who back up the idea of peaceful coexistence," it said.
Insults to Islam are taken very seriously in deeply conservative Afghanistan, where the Taliban are fighting a 10-year insurgency against 117,000 NATO troops and the US-backed government.
Riots killed around 40 people earlier this year after US troops burnt copies of the Koran on a military base.
The Taliban issued a statement calling on its to fighters to take revenge against the American government over the film "by dealing a heavy blow to its invading troops on the battlefield".
It also called on religious scholars to "inform the masses about such barbaric acts of America in their sermons and to prepare them for a lengthy struggle".
Presidency spokesman Aimal Faizi told AFP that the eruption of possible protests over the film "is an issue of concern" and said that officials had been instructed to be vigilant.
But there was confusion over whether or not the government had briefly banned YouTube in an effort to stop the film being seen.
Communications ministry official Aimal Marjan told AFP that the website had been "temporarily blocked" for almost 90 minutes.
Faizi confirmed that the information and culture ministry had requested a ban, but only of the film itself, and had been informed by the telecommunications ministry that it would be impossible to ban the film entirely in Afghanistan.
He said that instead there had been a "technical issue" that left YouTube briefly inaccessible.
The trailer remained accessible on YouTube in Afghanistan late Wednesday.