Visitors to the Flight 93 National Memorial in Shanksville, Pennsylvania, participate in a memorial service Thursday, as the nation marks the 14th anniversary of the September 11 attacks. Photo: AP

Relatives of the nearly 3,000 people killed in the September 11, 2001, attacks gathered in New York, Pennsylvania and outside Washington on Friday to mark the 14th anniversary of the hijacked airliner strikes carried out by Al Qaeda militants.

In New York, relatives of the victims read their names in a solemn and poignantly familiar pattern.

Emblematic of the generations affected, children who were not old enough to remember their late relatives or had yet to meet them participated in the roll call.

They stood at the empty footprint of the World Trade Center Twin Towers, toppled by two hijacked airliners on that clear, sunny morning in 2001.

Hijackers crashed two other commercial jets into the ­Pentagon in Arlington, Virginia and into a field in Shanksville, Pennsylvania.

The New York ceremony punctuated by moments of silence to mark the times when each of the four planes crashed and the towers fell.

In Washington, President Barack Obama and First Lady Michelle Obama, joined by staff, bowed their heads for a brief moment of silence on the south lawn of the White House to mark the anniversary. 

Defense Secretary Ash Carter led a remembrance ceremony for relatives of those killed at the Pentagon.

Relatives of the 40 passengers and crew members who died aboard United Airlines Flight 93 gathered at the newly dedicated Flight 93 National Memorial in Shanksville.

The passengers are believed to have fought back against the hijackers, who crashed the plane upside down.

The first plane slammed into the North tower at 8:46 am, followed by a ­second plane hitting the South tower at 9:03 am.