MELISSA BLOCK, HOST:
Violence shook Afghanistan for a third day, following an admission by U.S. officials. They said several copies of the Quran were burned at a NATO base.
President Obama offered an apology in a letter to the Afghan president, saying the burnings were unintentional. President Karzai has issued an appeal for calm, but his message is competing with press releases from the Taliban calling for attacks on Western troops and Afghans who work with them.
At least one Afghan appears to have followed through today, killing two American service members.
NPR's Quil Lawrence has more from Kabul.
QUIL LAWRENCE, BYLINE: Even rumors that a Quran has been desecrated, even thousands of miles away in Florida or Guantanamo have, in the past, caused deadly riots that saw buildings put to the torch across Afghanistan. This time, American officials admitted it is true. They say soldiers accidentally burned several Qurans, along with what was considered radical religious materials.
After three days of slogans and stone throwing, today, the violence went a step further.
HAJI MOHAMMAD HASSAN: (Foreign Language Spoken).
LAWRENCE: Haji Mohammad Hassan, a district governor from the eastern province of Nangarhar, said about 500 people were protesting outside a joint American-Afghan military base. Without warning, an Afghan army soldier turned his gun on the Americans, killing two of them.
Hassan said several protesters were killed and wounded in the ensuing firefight, but the gunmen escaped into the crowd. It's only the latest in a series of incidents recently where Afghan soldiers murdered their NATO trainers, but this one appeared to be directly related to the Quran incident.
The Taliban issued statements encouraging the Afghan people to rise up against the foreign troops occupying the country. Even before the Taliban statement, half a dozen provinces had seen deadly clashes between angry mobs and Afghan police.
ABDEL SATAR BAREZ: (Foreign language spoken).
LAWRENCE: Abdel Satar Barez, deputy governor of western Faryab Province, said a peaceful protest by clerics gave way to a mob of 400 that set fire to cars belonging to Afghan civilians who work at a NATO base. By evening local time, President Karzai had received a formal apology from President Obama. Karzai released a statement appealing for calm, but tomorrow's Friday prayer is a traditional medium for political, as well as religious, messages. Even some members of the Afghan parliament have called for a holy war against Americans because of the incident.
Afghan and U.S. forces are bracing for another day of anger and violence. The commander of American forces has announced that all soldiers will receive training on how to respect religious items, but many Afghans are wondering, after 10 years and several similar riots in the past, how such a mistake could have occurred.
Quil Lawrence, NPR News, Kabul.