9/11 commemoration: New York Skyline lit up with twin lights at World Trade Center

Ahead of the eleventh commemoration of the 9/11 attacks, the New York Skyline has been lit up with twin lights, filling the hole left by the World Trade Center.

The bright beams shooting up into the sky are turned on every September 11, and today’s 11th anniversary is no different.

Memorial services are set to take place at Ground Zero and hundreds of other venues around the globe.

One tribute to the victims comes at Highland Memorial Park in Ocala, Florida, where 2,741 American flags – one for each of the attacks’ victims – have been planted in a moving act of remembrance.

On Monday, Leon Panetta attended a ceremony at the Flight 93 National Memorial in Shanksville, Pennsylvania.

The Secretary of Defense called the site “the final resting place of American patriots”, and said he was there “to extend our nation’s deepest gratitude to the heroes of Flight 93”.

For the first time, the memorial ceremony at the 9/11 National Memorial in Manhattan will not feature any politicians this year, in an attempt to focus it on the private grief of survivors and victims’ relatives.

Barack Obama and Mitt Romney are expected to limit their campaigning, and to cancel negative advertising for the day.

The President has been briefed by top national security aides on what steps the government was taking to reduce the possibility of reprisal attacks on the 9/11 anniversary.

The White House said on Monday that Barack Obama and his advisers discussed specific measures the administration was taking to prevent related attacks.

They also discussed steps that were being taken to protect Americans abroad and U.S. forces serving in combat zones.

Barack Obama has instructed government agencies to do everything possible to protect the American people both at home and abroad.

The attacks on the World Trade Center and the Pentagon on September 11, 2001 killed nearly 3,000 people and led to long-running U.S. wars in Afghanistan and Iraq.