Afghan policemen keep watch near the wreckage of a burned-out vehicle at the UN headquarters in Mazar-i-Sharif on April 2, 2011, after protesters attacked the compound April 1.
New and deadly protests over the burning of a Koran flared up on Saturday in the city of Kandahar, a day after riots in northern Afghanistan left seven United Nations employees and four Afghans dead.
Ten people were killed and at least 81 injured in Kandahar as mobs roamed the city smashing shop windows, burning cars and vandalizing a girls' high school, according to local officials. At least 20 have been arrested, including seven who had weapons.
The protests were fuelled by anger that an obscure Florida pastor made a show of destroying a Koran last month. But their violence in Kandahar and, a day earlier, in the normally peaceful city of Mazar-i-Sharif demonstrated how quickly any large gathering in Afghanistan can bring anti-Western sentiment boiling to the surface.
A spokesman for the Kandahar provincial governor blamed Taliban insurgents and sympathizers for infiltrating the protest, which began with a march of about 100 stick-wielding men and boys and ballooned to a mob of several thousand over the course of the morning.
Afghan police and American soldiers fought back a crowd that tried to storm a complex of government buildings in Kandahar, a stronghold of the insurgency that has seen a string of assassinations of local officials and suicide bombings in the past two months.
Many of the people injured were beaten and stoned by the protesters when they refused to join in the rampage, according to witnesses and hospital officials.
"We did the protest to show to the infidels that we are unhappy about their action in burning our holy Koran in America," said a protestor, Gulab Shah, who described himself as a wood-seller.
Using the language usually found in Taliban statements, Mr. Shah complained that American soldiers and the "slave" Afghan government forces prevented the demonstrators from reaching the local UN office.
In Mazar-i-Sharif, police said they arrested the suspected ringleader of the attack on the UN compound along with about 20 other people. They identified the suspect as a militant from Kapisa province, about 400 kilometres southeast of the city.
The Afghan Ministry of Interior, whose riot police are trained by the NATO forces battling the insurgency, announced it was launching an investigation into how its officers handled the attack.
"The police did take action, but we are investigating how these casualties occurred," said Zemeri Bashary, the ministry spokesman. "Were the steps and actions by police adequate or not?"
Unlike Kandahar, which has a heavy foreign troop presence, Mazar-i-Sharif is patrolled largely by local police and army units.
It is one of four provincial capitals that where Afghan forces are to assume full security control beginning in July, under a NATO transition plan that is intended to give Afghans the lead responsibility for security in their country by the end of 2014.