Obama sends letter of apology to Afghan president
By AMIR SHAH and PATRICK QUINN, Associated Press
Feb 23, 2012 6:58 AM CST
Security guards stand as black smoke rises from tyres which were burnt by protesters during an anti-US demonstration in Kabul, Afghanistan, Wednesday, Feb. 22, 2012. Anti-American demonstrations erupted on the outskirts of Kabul for a second day Wednesday and in another Afghan city over an incident...   (Associated Press)

The Afghan president's office says it has received a letter from President Barack Obama formally apologizing for the burning of Qurans at a U.S. military base in Afghanistan.

The statement from President Hamid Karzai's office says the U.S. ambassador delivered the letter on Thursday.

In the letter, which is quoted in the statement, Obama expresses his "deep regret for the reported incident" and offers his "sincere apologies."

According to the statement, Obama wrote: "The error was inadvertent; I assure you that we will take the appropriate steps to avoid any recurrence, to include holding accountable those responsible."

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.

KABUL, Afghanistan (AP) _ An Afghan official says two protesters have died in an exchange of gunfire during a riot outside an American base in eastern Afghanistan that also wounded two NATO troops.

The deaths raise to five the number of Afghans killed around the country during Thursday's protests over this week's Quran burnings at a U.S. base.

Governor Haji Mohammad Hassan says NATO and Afghan troops were firing in the air to disperse hundreds of protesters gathered in front of the base in Khogyani district in eastern Nangahar province.

Hassan says during the rioting, one man in an Afghan army uniform shot at NATO troops and seriously wounded two of them.

Earlier, Afghan police shot and killed three protesters during two demonstrations in the north and south of the country.

See 1 more photo