President Barack Obama attended the 8th anniversary of 9/11 on Friday with about 500 people under rain-filled skies at the Pentagon.

Let us renew the true spirit of that day not the human capacity for evil but the human capacity for good, Obama said during the ceremony.

Not the desire to destroy but the impulse to save and to serve and to build, he said.

He also issued a proclamation on Thursday honoring those who died and urging Americans to mark the anniversary with acts of community service.

In pursuit of al Qaeda and its extremist allies we will never falter, he said, before laying a wreath at a memorial for those killed at the Pentagon on September 11, 2001.

Al Qaeda hijackers took control of four passenger planes on September 11, crashing two into the World Trade Center in New York and a third into the Pentagon. A fourth, United Airlines Flight 93, crashed into a field in Pennsylvania after the passengers and crew tried to retake control of the plane.

In all, about 3,000 people were killed.

President Barack Obama and first lady Michelle Obama take part in a moment of silence marking the eighth anniversary of the September 11 attacks on New York, Washington, and Pennsylvania, on the South Lawn at the White House in Washington, September 11, 2009. REUTERS/Jim Young
Family members of victims console each other as they gather to pay their respect at the reflecting pool at Ground Zero during the eighth anniversary commemoration ceremony of the 9/11 attacks on the World Trade Center in New York, September 11, 2009. REUTERS/David Handschuh/Pool
Secretary of Defense Robert Gates (R) holds his hand over his heart next to President Barack Obama (L) while at a Pentagon ceremony on the eighth anniversary of the attacks against the United States of September 11, 2001 in Arlington, September 11, 2009. REUTERS/Larry Downing
A sign memorializing a victim of the 9/11 attacks on the World Trade Center is carried at Ground Zero during the eighth anniversary commemoration ceremony in New York, September 11, 2009. REUTERS/Chang W. Lee/Pool
A man prays at the reflecting pool during the eighth anniversary remembrance of the attacks on New York and Washington, in New York, September 11, 2009. REUTERS/Chip East
Marta Waisman holds a photo of her daughter Gabriela, who lost her life in the September 11, 2001 attack on the World Trade Center in New York City September 11, 2009. REUTERS/Robert Sciarrino/Pool
Barack obama