In pictures: Remembering 9/11

Americans have been remembering the dead on the seventh anniversary of the 11 September attacks, in which nearly 3,000 people died.

A ceremony in downtown Manhattan marked the times when the planes hit the World Trade Center's Twin Towers, and when each structure fell - pausing for silence at 0846, 0903, 0959 and 1029.

The names of all those who died were read out loud by family members at New York's Ground Zero, now a construction site.

As part of the ceremony, families and friends of those who perished dropped flowers in a reflecting pool in honour of their loved ones.

Presidential rivals John McCain and Barack Obama walked shoulder-to-shoulder to lay flowers at Ground Zero. The Republican and Democratic candidates suspended campaigning for the day.

In Washington, President George W Bush, his wife Laura, Vice-President Dick Cheney and his wife Lynn observed a minute's silence on the lawn of the White House.

Thousands later looked on outside the Pentagon as Mr Bush dedicated a new memorial, made up of 184 concrete benches - one for each of the victims there.

Row upon row of US flags stood outside the Pentagon, in Arlington, Virginia.

A memorial was also held in Shanksville, Pennsylvania, for the people killed aboard hijacked flight United 93.

In Afghanistan, US servicemen held a ceremony at Bagram air base, north of Kabul. The 9/11 attacks triggered a US-led offensive to topple the country's Taleban regime and hunt al-Qaeda's leadership.

US troops in Iraq held their own ceremonies to mark the day. The 9/11 attacks sparked the Bush administration's "war on terror", and are regarded as the defining moment of Mr Bush's time in office.