US President Barack Obama sent Afghan President Hamid Karzai a letter of apology over the burning of copies of the Koran overseen by a US officer at a US military base, Karzai's office said Thursday.
Obama said the incident was unintentional and pledged a full investigation, the president's office said, as fierce anti-US protests swept the nation in which at least 14 people have died, including two American soldiers.
"I wish to express my deep regret for the reported incident," Obama wrote in the letter presented to Karzai by US ambassador Ryan Crocker. "I extend to you and the Afghan people my sincere apologies."
"The error was inadvertent; I assure you that we will take the appropriate steps to avoid any recurrence, to include holding accountable those responsible," the letter said.
Karzai told members of parliament that a US officer was responsible for the burning that was done "out of ignorance", his office said.
The incident at the US military base at Bagram north of Kabul sparked three days of fierce anti-US protests in which at least 12 protesters were killed.