The attacks killed nearly 3,000 people and prompted then-President George W Bush to launch a 'global war on terror' that included a military assault on Afghanistan to find al Qaeda leader Osama bin Laden.

The service at Ground Zero where 2,753 people died took place under tight security, with Lower Manhattan effectively locked down.

An expert does not rule out the possibility of attempts to replicate the 2001 attacks on the New York twin towers, but believes Malaysia is more prepared now.

He and the first lady will go to the three locations of the Sept 11, 2001 attacks: New York, the Pentagon and a field in Pennsylvania.

Do more counter-terrorism laws make people safer?

Attorneys say the defendants – Mohammed, Ammar al-Baluchi, Walid bin Attash, Ramzi bin al-Shibh and Mustafa al-Hawsawi – are all weak and suffer the lasting effects of severe torture endured in CIA 'black' sites.

Students in Australia speak of the pressure to self-censor and manage political and religious expression at school.

Declassification must take place over the next six months.

It cites increased use of 'online forums to influence and spread violent extremist narratives and promote violent activity'.

The FBI's commitment is part of a legal battle waged by relatives of Sept 11 victims against Saudi Arabia and other nations they believe were accomplices.