WASHINGTON (CBSDC/AP) — President Obama is remembering the nearly 3,000 lives lost during the 11th anniversary of the 9/11 terrorist attacks during official ceremonies in Washington, D.C., Tuesday.

The president and first lady Michelle Obama observed a moment of silence on the White House South lawn at 8:46 a.m. ET, the time that terrorists flew American Airlines Flight 11 into the World Trade Center’s north tower.

The Obamas then laid a white floral wreath at the Pentagon, above a concrete slab that said “Sept. 11, 2001 — 937 am.” He later recalled the horror of the attacks, declaring, “Our country is safer and our people are resilient.”

Obama reiterated in his speech at the Pentagon that the real enemy is al-Qaeda and not Islam.

“I’ve always said that our fight is with al-Qaeda and its affiliates, not with Islam or any other religion.”

The Obamas also went to Arlington National Cemetery to visit the graves of service members killed in Afghanistan and Iraq.

They quietly walked between rows of graves at Section 60, which contains the remains of the most recent war dead. Pausing at several graves, Obama placed presidential “challenge” coins at the base of the headstones. The first headstone listed the names of 10 victims of an Oct. 26, 2009, helicopter crash in Afghanistan.

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