Bagpipes and a youth choir opened the memorial service at the National September 11 Memorial plaza in New York on Wednesday. More than 1,000 people gathered for the annual reading of the names of victims killed on 9/11 and in a 1993 car bombing outside the World Trade Center.

Many of those reading from the list of names spoke directly to lost loved ones in emotional tributes.

"Cathy, your brothers and sisters still miss you. All the people whose lives you touched," said Eleanor Salter, whose daughter, Catherine Patricia Salter, perished. "As for me, life goes on. But it would have been really fun with you around. I miss your smile."

Former New York Mayor Rudolph Giuliani, his successor Michael Bloomberg, Police Commissioner Raymond Kelly, and other city and state leaders were attended the New York service, held around two memorial fountains that mark the footprints of the Twin Towers which collapsed in the 2001 attacks.

Americans observed a minute's silence at 8:46 a.m. local time (1246 GMT), when the first plane crashed into the North Tower. There was a second pause at 9:03 a.m. when the South Tower was hit.

Quiet fell again at 9:37 am when American Airlines Flight 77 hit the Pentagon in Washington, killing 184 people. More moments of silence came at 9:59 am when the South Tower collapsed, at 10:03 am when a fourth airliner hit the ground near Shanksville, Pennsylvania after passengers intervened, and finally at 10:28 am when the North Tower fell.

Obama tribute resonates amid Syria crisis

US President Barack Obama attended the Washington memorial where he paid tribute to the victims of the attacks as well as American soldiers, diplomats and intelligence agents who have died since 2001.

"Our hearts still ache for the futures snatched away, the lives that might have been," Obama said at the Pentagon. "They left this Earth. They slipped from our grasp."

Al Qaeda and Osama bin Laden claimed responsibility for the September 11 attacks prompting the US war in Afghanistan and indirectly leading to the war in Iraq.

Obama's speech at the Pentagon came the morning after he set out his justification for the use of military force in Syria, in the wake of chemical attacks on Damascus suburbs. In a televised address Obama called off an imminent military strike while the world debates a new diplomatic avenue to halt the use of chemical weapons.

In his tribute on Wednesday Obama noted the United States would remain vigilant in the face of future terror threats but said military might alone could not bring peace and security.

"Let us have the wisdom to know that while force is at times necessary, force alone cannot build the world we seek," he said.

ccp/ch (AFP, Reuters)