|Al Jazeera's Cath Turner reports on commemorations held for the ninth anniversary of the September 11 attacks
Barack Obama, the US president, has marked the ninth anniversary of the attacks against the United States on September 11, 2001, by saying his country is not at war with Islam.
The president's remarks came amid controversies over a planned Islamic centre to be built near the so-called Ground Zero site of the New York attack and a Florida pastor's plans to burn Qurans to "send a message" on the anniversary of the attacks.
A series of commemorations took place on Saturday to honour the nearly 3,000 people killed when members of al-Qaeda hijacked four planes, crashing two of them into the World Trade Centre and another into the Pentagon.
In New York, the names of the victims who died there were read out - as they are every year - at the Ground Zero site, against a background of sombre music at a service attended by Joseph Biden, the US vice-president.
Obama attended a memorial service at the Pentagon, while a separate service took place in Shanksville, Pennsylvania, where the fourth hijacked airliner crashed into a field.
Obama used his memorial speech to call once again for religious tolerance, as the day threatened to be overshadowed by a fringe US pastor's threat to burn copies of the Quran on Saturday.
The threat by Terry Jones, which was later withdrawn, has sparked protests around the world have and has been heavily criticised by Americans on both sides of the political divide.
"As Americans, we will not and never will be at war with Islam,"' Obama said.
"It was not a religion that attacked us that September day. It was al-Qaeda, a sorry band of men which perverts religion."
On Friday, thousands of Muslims in countries including Afghanistan, Pakistan, India, Indonesia and the Palestinian territories took to the streets to protest against the pastor's threat.
The rallies continued on Saturday in the Afghan provinces of Badakhshan and Logar.
Jones offered to scrap the plan to burn the Qurans on Thursday if an Islamic centre being built two blocks away from the Ground Zero site was relocated.
The pastor flew on Saturday to New York to hold talks with Imam Feisal Abdul Rauf, the leader of the planned Manhattan Islamic centre and mosque.
Rauf, however, denied both that developers of the project, currently called Park51, had agreed to move the centre or that he was meeting Jones.
Jones, who leads a small congregation of around 50 people, said on Saturday that he would "not today, not ever" burn copies of the Quran after pleas from Obama, the Vatican and several other world leaders warning of a catastrophe for Western-Muslim relations.
"We will definitely not burn the Quran, no," he told NBC's Today show, adding that his decision was no longer dependent on the location of the Islamic centre.
The US president has warned that the burning of Islam's holy book could provoke al-Qaeda suicide bombings and incite violence around the world.
Rallies by groups supporting and opposing the Park51 project took place near Ground Zero soon after the official ceremonies. Police were standing guard outside the block, and they attempted to keep the two sides from coming into conflict, though some scuffles were reported.
The site, which is already used for Muslim prayer services, has been closed until Sunday, and worshippers were being redirected to a different prayer room 10 street blocks away.
Al Jazeera's Kristen Saloomey, reporting from New York, said that the atmosphere in the city had been muted. "This is a sombre occasion. Family members of the victims have been reading their names, the pain and emotion that they feel still very evident," she said.
"But over this all is controversy about plans to build an Islamic community centre two blocks from the site. It has been a very contentious debate, at times an ugly and heated debate, with the majority of Americans thinking that this centre should not be built so close to where the World Trade Centre stood."