Differing opinions: Matt Sky, of Manhattan, supports the proposed mosque near Ground Zero. He had a heated debate with Rose Van Guilder, West Sayville, New York, and Lance Corey of Ossining, New YorkThousands gather at Ground Zero, Pennsylvania and the Pentagon
Police braced for violence as rival mosque protests are held in New York
Obama: 'We are not at war with Islam'
U.S. flags burnt in Afghanistan and Pakistan
Tensions flared in New York this afternoon as rival demonstrations over the Ground Zero mosque overshadowed a day of mourning to mark the ninth anniversary of the 9/11 terror attacks.
Two marches were taking place just a few blocks apart, one in support of the mosque and the other in protest against it.
The rival demonstrations began shortly after the families of 9/11 victims held moving ceremonies to remember loved ones killed in the atrocities nine years ago.
Many voiced their anger at the rival demonstrations and called called for ‘sombre reflection’ instead of what has become the most divided September 11 anniversary yet.
Clash: Supporters and opponents of the mosque held simultaneous marches in downtown Manhattan today. Predictably, tempers flared when the groups met and ploice were forced to break up many arguments Shortly after the ceremonies, a large crowd of pro-mosque activists lined two blocks next to City Hall before marching to an area near Ground Zero.
Elizabeth Meehan, a 51-year-old Christian from Saratoga, New York, said: 'I'm really fearful of all of the hate that's going on in our country. People in one brand of Christianity are coming out against other faiths, and I find that so sad.'
'Muslims are fellow Americans; they should have the right to worship in America just like anyone else.'
The event was largely peaceful, except for occasional exchanges with anti-mosque passers-by.
Strong opposition: Americans travelled from across the country to participate at a rally against the mosque on the ninth anniversary of the 2001 terrorist attack on New York One man walked by holding a poster that said, 'Stop Obama's Mosque,' while another held a more provocative sign with a Quran attached.
At the anti-mosque rally nearby, some participants wore clothing featuring stars and stripes, and some carried signs with messages including 'It stops here' and 'Never forgive, never forget, no WTC mosque.'
'My grandparents didn't expect special treatment. They didn't fly planes into buildings,' said Theresa Angelo, 57, from Queens.
'No other culture does that. This is hallowed ground. It's something like Gettysburg or Pearl Harbor. Why did they have to do it here? Be a little sensitive.'
Time for reflection: A boy kneels in silence at the edge of a reflecting pool filled with flowers during a memorial service at Ground Zero today
Remembering the fallen: President Barack Obama pauses during a ceremony today at the Pentagon
Making feelings plain: Alyson Low, of Fayetteville, Arkansas, shrugs off the controversy over the planned mosqueAnti-Islam Dutch politician Geert Wilders, who advocates banning the Quran and taxing Muslim women who wear head scarves, planned to address the crowd in person, along with a handful of Republican congressional candidates who have made opposition to the mosque a centerpiece of their campaigns.
Earlier, family members gathering n New York, Pennsylvania and the Pentagon brought flowers, pictures of their loved ones and American flags as the victims' names were read out.
Standing before microphones, stifling sobs, some family members expressed their thoughts about the furore surrounding plans to build a mosque near Ground Zero.
Karen Carroll, who lost her brother, firefighter Thomas Kuveikis, said: ‘It's a day to be sombre; it's a day to reflect on all those thousands of people that died for us in the United States.’
Grief: Anna Sereno holds a portrait of her son Arthuro Angelo Sereno, killed during the attacks on the World Trade CentreOthers mourners made their feelings plain with placards.
Alyson Low, of Fayetteville, Arkansas, held a photo of her sister Sara Low beside the words: ‘Today is ONLY about my sister and the other innocents killed nine years ago.’
The mother of a British victim of the 9/11 attacks criticised the pastor for adding to the ‘burden’ suffered by families on the anniversary of the deaths of their loved ones.
Patricia Bingley, from Essex, whose son Kevin Dennis worked in the World Trade Centre, told the BBC: ‘We have enough burden to bear without having to listen to this crank, as I call him, threatening to burn a very sacred book belonging to the Islamic community.
‘To me the repercussions if this act was to take place would reverberate right the way through the Muslim world.
‘I am just as much against that as I am against having a mosque built next to the site because that's my son's grave - I don't have any other grave.
‘I think it's disrespectful to build a mosque just there.'
Scene of tragedy: Members of the victims' families gather at Ground Zero todaysource: dailymail