KANDAHAR, Afghanistan (Reuters) - At least 10 people have been killed and 83 wounded in the southern Afghan city of Kandahar, officials said on Saturday, on a second day of violent protests over the burning of a Koran by a radical fundamentalist Christian in the United States.
A suicide attack also hit a NATO military base in the capital Kabul, the day after protesters over-ran a U.N. mission in the northern city of Mazar-i-Sharif and killed seven foreign staff, in the deadliest attack on the UN in Afghanistan.
Some protesters in Kandahar carried white Taliban flags and shouted slogans including "long live the Taliban" and "death to America." In rioting that lasted hours, they smashed shops, burned tires and vandalized a girl's high school.
Two of the dead were Afghan policemen, an official said.
The violence is the worst in Afghanistan for months, and comes as the country gears up for the first stage of a years-long security handover to Afghan troops, and after the commander of U.S. and NATO forces in Afghanistan, General David Petraeus, delivered an optimistic assessment of progress in the war.
The attacks were driven by anger at the actions of extremist Christian preacher Terry Jones who supervised the burning of the Koran in front of about 50 people at a church in Florida on March 20, according to his website.
The burning initially passed relatively unnoticed in Afghanistan, but after criticism from President Hamid Karzai, and calls for justice during Friday sermons, thousands poured into the streets in several cities to denounce Jones this weekend.
Afghan and U.N. officials suggested provocateurs had sabotaged peaceful protests. Marches in Kabul, western Herat city and northern Tahar province ended without violence.
But the Taliban denied any role in the Mazar attack or Kandahar protests and analysts warned against underestimating the depth of anti-Western sentiment in much of Afghanistan, after years of military presence and many civilian casualties.
"Insurgent provocation is not necessary for things like (the U.N. attack) to happen, because indeed the mood and atmosphere in a large part of the population is like this," said Thomas Ruttig, co-director of the Afghanistan Analysts Network.
"Anger over foreigners in general, which has probably spread from the military to NGOs and the U.N. and other actors, just needs a little spark and things can be set alight."
In Kabul on Saturday, a small group of burkha-clad insurgents attacked a coalition base, although they caused only light injuries to three soldiers, police and NATO said.
In Kandahar, one of the policemen killed and several civilians died from gunshot wounds, said Abdul Qayum Pukhla, the senior health official for the province. The rest of the dead had been beaten and stoned he added.
It was not clear if gunshot wounds were caused by protesters or police trying to control them over hours of rioting.
A band of around 150 men who had taken to the streets to denounce the Koran burning set tires alight, smashed shops and assaulted an Afghan photographer, Reuters' witnesses said. Some of the attackers were carrying guns.
The photographer was hit over the head and had his camera taken from him and smashed, by protesters who discussed killing him. Police kept other journalists from approaching the crowd.
In the violence they also smashed windows and burned chairs at the Zarghona High School for girls. The Taliban opposed girls' education, and Kandahar was their spiritual heartland.
The spokesman for the governor of Kandahar province said the protest was organized by the Taliban who used the Koran burning as an excuse to incite violence in a city where their reach has been curtailed by an aggressive NATO-led military campaign.
The Taliban said they had no role in the Kandahar violence or Friday's assault on the U.N. office in the usually peaceful city of Mazar-i-Sharif, after both provincial governors and a senior U.N. official suggested an insurgent role.
"The Taliban had nothing to do with this, it was a pure act of responsible Muslims," spokesman Zabihullah Mujahid said by phone from an undisclosed location of the Mazar attack. He later added that the Kandahar demonstration was also spontaneous.
Interior Ministry spokesman Zemari Bashery said police reports suggested the attack was not planned.
Around 5,000 demonstrators flooded into the streets of a city considered safe enough to be in the vanguard of a crucial security transition, after Friday prayers ended, and many headed straight for the U.N. mission.
There they overwhelmed security guards, burned parts of the compound and climbed blast walls to topple a guard tower. The throat of one of slain foreigners had been slit, the U.N. said.
Five Afghan protesters were also killed and others wounded, some after trying to take weapons off U.N. security guards.
The attack took many in the city, one of the country's most prosperous and stable, by surprise. Some were horrified by the extreme violence but not all had sympathy for the foreign dead.
"I took part in the demonstration to curse the foreigners but I had no weapon," said shopkeeper Rahim Mohammad.
"But I don't feel sorry for UN workers killed, our people are slaughtered by foreigners everyday."
More volatile protests are possible across deeply religious Afghanistan, where anti-Western sentiment has been fueled for years by civilian casualties, and the Taliban.
Additional reporting by Hamid Shalizi in KABUL and Ismail Sameem in KANDAHAR, writing by Emma Graham-Harrison; Editing by Jeremy Laurence