Tensions over a threat to burn the Koran in Florida and a proposed Islamic center near New York's Ground Zero marked the ninth anniversary on Saturday of the September 11 attacks on the United States. Shortly before the start of ceremonies in New York, Washington and Pennsylvania to remember the day nearly 3,000 people lost their lives, Florida preacher Terry Jones confirmed he had backed off his plan to burn the Islamic holy book. "We have decided to cancel the burning," Jones, the head of the tiny Dove World Outreach Center in Gainesville, Florida, told NBC's "Today" show on Saturday. But news of the plan had outraged Muslims around the world and triggered outbreaks of violence in Afghanistan in which one protester was shot dead. Thousands of Afghans demonstrated in the northeast of the country for a second day on Saturday. President Barack Obama and U.S. officials had warned that the burning of the Koran could harm America's image abroad, endanger lives and act as a recruiting tool for al Qaeda. He told a memorial service in Washington that those who attacked the country with hijacked planes on September 11, 2001, tried to deprive Americans of their ideals. "They may seek to spark conflict between different faiths, but as Americans we are not and will never be at war with Islam. It was not a religion that attacked us that September day, it was al Qaeda -- a sorry band of men that perverts religion," he said. As Obama spoke at the Pentagon, family and friends of those who died in the New York attacks placed flowers in a pool at the site. The names of the 2,752 World Trade Center victims were read out loud in alphabetical order during the somber ceremony. Jones, who had arrived in New York from Florida on Friday night, said he came with the hope of meeting the New York imam Feisal Abdul Rauf, who is involved in the proposed Islamic center and mosque near the Manhattan site of the attacks. Although no meeting was planned, the bewhiskered fundamentalist preacher who said he had received 100 death threats, hoped to persuade Rauf to relocate the project. OPPOSITION TO CENTER Supporters and critics of the New York Islamic center planned protests on Saturday at the proposed site after the ceremony. Critics say it is insensitive to the families of the victims of the 2001 attacks. Obama said on Friday he recognized "the extraordinary sensitivities" surrounding the September 11 attacks. But he said it should be possible to erect a mosque near the attack site, or a building representing any other kind of religion. Several thousand people gathered in Afghanistan's northeastern Badakhshan province on Saturday, where a day earlier a protester was killed outside a German-run NATO base, provincial police chief Aqa Noor Kentuz said. A day before Saturday's anniversary, the former heads of the 9/11 Commission that studied the 2001 attacks presented a report they called a wake-up call about the radicalization of Muslims in the United States and the changing strategy of al Qaeda and its allies. "The threat that the U.S. is facing is different than it was nine years ago," said the report by the Bipartisan Policy Center in Washington. "The U.S. is arguably now little different from Europe in terms of having a domestic terrorist problem involving immigrant and indigenous Muslims as well as converts to Islam."