Violent protests in Afghanistan flared for a second day today, enflamed by outrage over the burning of a Quran by Florida pastor Terry Jones.
Nine protesters were killed today in Kandahar, where hundreds marched holding copies of the Quran when security forces shot into the air to disperse the crowd.
Zalmai Ayubi, a spokesman for the provincial governor, said it is unclear how the protestors were killed.
"Some wicked and destructive people placed themselves amongst the protesters and started rioting throughout the entire Kandahar city. The enemies of the people and country also burned down the furniture and a bus at a ladies' high school in Kandahar and destroyed some other properties," said a statement from the governor's office, according to The Associated Press.
Anger over Terry Jones' burning of the Quran began on Friday in the town of Mazar-i-Sharif, when 11 people were killed -- including seven United Nations workers -- at a United Nations compound.
"We wanted to raise awareness of this dangerous religion and dangerous element," Jones said. "I think [today's attack] proves that there is a radical element of Islam."
"We decided to put the Quran on trail," he told ABC News. "I was the judge but I did not determine the verdict. I was just a type of referee so that people got their time to defend or condemn the Quran."
Jones said that a "jury" of people from all over Florida debated the radicalism of Islam, and the "Quran was found guilty."
"If the Quran was found guilty then there were four forms of punishment: burning, shredding, grounding, a firing squad," he said. "The one that the people chose was burning. That is why the Quran was burned after it was found guilty."
The Afghan protests Friday started peacefully but took a violent turn after a radical leader told those gathered that multiple Qurans had been burned. People angrily marched on the nearby U.N. compound, despite police who fired AK-47s into the air in hopes of subduing them.
Police eventually turned their weapons on the protesters, killing at least four, police said, before they were overtaken and had their guns stolen.
Using the police weapons, the protestors killed four U.N. guards from Nepal and then three foreign workers in the U.N. building -- a Norwegian, a Romanian and a Swede.
An Afghan official said one man has been arrested for allegedly masterminding the attack along with 19 others, according to a report by the AP.
Despite an onslaught of attention Jones got when he initially made his threat to burn the Muslim holy book in September 2010 -- including a personal plea from President Barack Obama -- the actual burning of the Quran last month on March 20 at Dove Outreach Center in Gainesville, Fla., went relatively unnoticed in western media.
Obama condemned the attack on the U.N. compound "in the strongest possible terms" in a statement.
"The brave men and women of the United Nations, including the Afghan staff, undertake their work in support of the Afghan people," Obama said. "Their work is essential to building a stronger Afghanistan for the benefit of all its citizens. We stress the importance of calm and urge all parties to reject violence and resolve differences through dialogue."
U.N. Secretary General Ban Ki-moon joined Obama in his condemnation of the attack Friday.
"This was an outrageous and cowardly attack against U.N. staff, which cannot be justified under any circumstances and I condemn it in the strongest possible terms," Ki-moon said from Kenya, where the United Nations said he is making an official visit.
Terry Jones Canceled Previous Quran Burning in New York
Jones initially cancelled his plans for the book burning on the ninth anniversary of the Sept. 11 terror attacks. The stunt, according to Jones, was a protest against the Muslim-backed community center that was to be built near the site of the September 11 attacks in New York.
During that initial incident, Gainesville's mayor told reporters Jones does not speak for the community.
"He's a really fringy character," said Pegeen Hanrahan, a two-term mayor who left office in May. "For every one person in Gainesville who thinks this is a good idea there are a thousand who just think it's ridiculous."
"He's a person who has a congregation that's exceedingly small, maybe 30 or 40 people -- 50 on a good day," Jacki Levine, managing editor of the Gainesville Sun newspaper, said in September. "He is not at all reflective of community he finds himself in."
ABC News' Lauren Effron and The Associated Press contributed to this report.