After the ceremony, around 1,000 activists rallied about five blocks from the site of the 2001 attacks to support the proposed Islamic community center. Opponents also planned to rally in the afternoon, with the two groups expected to converge near the mosque site.
Speaking at "hallowed ground" at the Pentagon, President Barack Obama alluded to the controversy over a mosque - and a Florida pastor's threat, later rescinded, to burn copies of the Muslim holy book. Obama made it clear that the U.S. is not at war with Islam and called the al-Qaida attackers "a sorry band of men" who perverted religion.
"We will not give in to their hatred," Obama said. "As Americans, we will not or ever be at war with Islam."
Family members gathering at observances in New York and Pennsylvania brought flowers, pictures of loved ones and American flags, but no signs of opposition or support for the mosque. Reading victims' names along with architects and construction workers rebuilding at ground zero in New York, they urged a restrained tone.
"Let today never, ever be a national holiday. Let it not be a celebration," said Karen Carroll, who lost her brother, firefighter Thomas Kuveikis. "It's a day to be somber; it's a day to reflect on all those thousands of people that died for us in the United States."
Toting signs saying, "The attack on Islam is racism" and "Tea Party Bigots funded by corporate $," protesters gathered about an hour after the New York anniversary ceremony ended near City Hall and planned to march closer to ground zero.
Elizabeth Meehan, a 51-year-old Christian from Saratoga, N.Y., rode in by bus from her home 180 miles away.
"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," she said. "Muslims are fellow Americans; they should have the right to worship in America just like anyone else."
At the anniversary ceremony, stifling sobs in front of microphones, some Sept. 11 family members who read names sought to emphasize sentiments on all sides of the mosque argument.
Some - like Elizabeth Mathers, whose father, Charles Mathers, worked at Marsh & McLennan at the trade center - stressed that ground zero is hallowed.
"New York, please be mindful this is a sacred site and should be respected as such," she said.
Many sought to embrace unity and a spirit of reaching out, which is what the developers of the Islamic center have said is their goal.
"May we share your courage as we build bridges with other people to prevent this from happening again and to preserve human dignity for all," said Robert Ferris, saluting the dozens of building workers who joined families in reading names.
Ferris lost his father, who worked at Aon Corp.
Bagpipes and drums played to open the ceremony, followed by brief comments by Mayor Michael Bloomberg.
"Once again we meet to commemorate the day we have come to call 9/11. We have returned to this sacred site to join our hearts together, the names of those we loved and lost," Bloomberg said. "No other public tragedy has cut our city so deeply. No other place is as filled with our compassion, our love and our solidarity."
Moments of silence were held at 8:46 a.m., 9:03 a.m., 9:59 a.m.
and 10:28 a.m. to mark the times the hijacked jetliners hit the north and south towers of the World Trade Center, as well as the times they collapsed.
Hundreds of family members later placed roses in a reflecting pool at ground zero in front of a memorial, leaving scrawled remembrances on paper around it. Visible behind the podium of mourners were the beginnings of two skyscrapers rising at the site along with a transit hub.
Laura Bush, first lady at the time of the attacks, joined current first lady Michelle Obama at a service in Shanksville, Pa., for victims of the flight that crashed in a field there, while the president attended the service at the Pentagon.
"May the memory of those who gave their lives here continue to be an inspiration to you and an inspiration to all of America," Michelle Obama said, thanking Bush for helping the country through the aftermath of Sept. 11.
The mosque debate pits advocates of religious freedom against critics who say putting an Islamic center so close to ground zero disrespects the dead. While the rallies in New York embroiled victims' family members in a feud over whether to play politics, a threat to burn copies of the Quran was apparently called off.
Terry Jones, the Florida pastor who made the threat, flew to New York on Friday night and appeared Saturday on NBC's "Today" show. He said his church would not burn the Quran, a plan that inflamed much of the Muslim world and drew a stern rebuke from Obama.
"We feel that God is telling us to stop," he told NBC. Pressed on whether his church would ever burn the Islamic holy book, he said: "Not today, not ever. We're not going to go back and do it. It is totally canceled."
Lending credence to Jones' comments, a "Burn a Koran Day" banner outside his Florida church was taken down.
Still, protests continued Saturday in Afghanistan. Police fired warning shots to prevent protesters from storming the governor's residence in Puli Alam in Logar province, officials said. Villagers set fire to tires and briefly blocked a highway to Pakistan, a provincial spokesman said.
Jones said that he flew to New York in the hopes of meeting with leaders of the Islamic center but that no such meeting was scheduled. Imam Feisal Abdul Rauf, leader of the planned mosque, had also said Friday he had no meeting planned with Jones.
Activists in New York insisted their intentions were peaceful. The demonstrations were expected to meet near the mosque building, a former clothing store two blocks north of the trade center site.
John Bolton, who was U.S. ambassador to the United Nations under President George W. Bush, was expected to send a videotaped message of support to the anti-mosque rally, as was conservative blogger Andrew Breitbart. Anti-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, as do a handful of Republican congressional candidates who have made opposition to the mosque a centerpiece of their campaigns.
Muslim prayer services are normally held at the site, but it was padlocked Friday and closed Saturday, the official end of the holy month of Ramadan. Police planned 24-hour patrols until next week. Worshippers on Friday were redirected to a different prayer room 10 blocks away.
Vice President Joe Biden spoke at the New York ceremony, where 2,752 people were killed when two jetliners flew into the trade center. More than 200 other people died in Pennsylvania and at the Pentagon.
Here is a list of events throughout the Valley that will mark the anniversary of the September 11, 2001, terror attacks.
Observance at 8:30 a.m. Saturday at the California Memorial, 3500 Pelco Way, Clovis.
(559) 292-1981, ext. 3433
Exeter American Legion Post 94:
Commemoration ceremony at noon Saturday at the Exeter Fire Station, 137 N. F St.
9/11 Stop the Violence Rally/Crusade:
March begins at 10:00 a.m. Saturday at California Avenue and Walnut Street in Fresno. (559) 222-3720
Madera Ranchos Assembly of God Church:
Classic car cruise-in in memory of 9/11 from 11:00 a.m. to 2:00 p.m. Saturday at the Madera Ranchos Maywood Center, Avenue 12 between Highways 41 and 99.
Visalia Fire Department
Memorial service at 9:00 a.m. Saturday at Fire Station No. 51, 309 S. Johnson St., Visalia.