US marks Sep 11 with moments of silence

Speaking near Ground Zero, where the twin World Trade Center towers were destroyed by hijacked planes on Sept. 11, 2001, Mayor Michael Bloomberg told families of those who died: "Six years have passed and our place is still by your side."

Rain fell on the somber ceremony as some wore funereal black to remember the 2,750 people killed when the towers were destroyed one after the other. Their names were due to be read out loud over four hours.

Similar ceremonies were taking place in Washington, where the Pentagon was attacked by a third plane, and Shanksville, Pennsylvania, where a fourth plane crashed after passengers fought with al Qaeda hijackers that day.

Bagpipes played, accompanied by a steady drum beat, in a New York city park neighboring the former disaster site which is now a busy construction zone.

The first of four New York moments of silence -- followed by the ringing of church bells -- took place at 8:46 a.m. (1246 GMT), the hour the first plane struck. Other moments were set for when the second plane struck and when each tower fell.