(VOVworld) – The United States is marking the 15th anniversary of the September 11 attacks with solemn services to commemorate the victims.

Police march in Lower Manhattan in memory of the officers killed during and after the attacks. (Photo: AFP/Spacer Platt)

The names of nearly 3,000 victims are read out in a remembrance service at Ground Zero in New York on the site of the rebuilt World Trade Centre. The service pauses six times to mark the six horror moments of the attack fifteen years ago. During the first moment of silence at 8:46 am, the time when American Airlines plane hit the north tower, houses of worship in New York have been asked to toll their bells. President Barack Obama will address a ceremony at the Pentagon. In his address on Saturday, Mr. Obama said that the US cannot make concessions to those who will separate the US.

On September 11, 2001, hijackers flied four planes into the twin towers in New York, Pentagon, and the area near Shanksville, Pennsylvania. Terrorist leader Osama bin Laden and Al-Qaeda claimed responsible for the attack. The US launched a global campaign to fight terrorism and opened war in Afghanistan. In May 2011, US special forces killed Osama bin Laden in a raid in Abbottabad, Pakistan.