KABUL, Afghanistan -- The Taliban movement on Thursday harshly denounced an amateur video mocking Islam, blaming "bestial" America for its production and urging that the Muslim world respond with "appropriate action."



Most Western installations in the Afghan capital were on high alert in advance of Friday prayers, which are the main religious event of the Muslim week and a sometime flash point for violent protests, especially if mosque preachers, or imams, take to the pulpit to condemn a perceived insult to Islam.



The crudely made video was thought to have sparked attacks Tuesday on U.S. diplomatic missions in Egypt and Libya, which left the U.S. envoy to Libya and three other Americans dead.



The Taliban statement said its fighters would redouble efforts to strike at U.S. bases and "invading" troops in retaliation for the video, and urged religious scholars to "fully inform the masses about ... barbaric acts of America" in their Friday sermons.



A day earlier, President Hamid Karzai issued a sharply worded statement calling the video a "desecrating act." In the past, such statements from the presidential palace have sometimes been taken by conservative religious leaders as tacit approval for whipping up angry street demonstrations.