US marks 21st anniversary of 9/11 terror attacks

The 9/11 anniversary commemoration at ground zero has begun with a tolling bell and a moment of silence, 21 years after the start of the deadliest terror attack on US soil.

Victims' relatives and dignitaries are gathering Sunday at all three places where hijacked jets crashed on Sept. 11, 2001 the World Trade Center in New York, the Pentagon and a field in Pennsylvania.

Vice President Kamala Harris and husband Doug Emhoff are attending the ceremony at the National Sept. 11 Memorial in New York. President Joe Biden plans to speak and lay a wreath at the Pentagon, while first lady Jill Biden is scheduled to speak in Shanksville, Pennsylvania.

The attacks killed nearly 3,000 people, spurred a U.S. war on terror worldwide and affect American politics and public life to this day.