At least five people have been shot dead and dozens of others wounded in a second day of protests in several Afghan cities.
The U.S. embassy says its staff are in "lockdown" status and travel has been suspended.
Protesters shouted "Death to America" and "Death to Karzai," the Afghan president, in a large demonstration on the edge of the Afghan capital of Kabul.
The Afghan parliament also expressed outrage with several members chanting against the U.S.
The protests have also spread to other Afghan cities.