As today marks 20 years since the 9/11 terrorist attacks perpetrated in the United States, Sri Lanka has expressed its solidarity with the people of the U.S. and their government who are commemorating a very painful episode in the country’s contemporary history.

“Sri Lanka also wishes to pay tribute to the many victims and survivors of the dastardly attacks,” the Ministry of Foreign Affairs said in a statement.

“As a country that has for long suffered from terrorism and successfully overcame its challenge on Sri Lankan soil, the Government of Sri Lanka also wishes to reiterate the need for all countries to unite in eliminating terrorism in all its forms and manifestations.”

On September 11, 2001 suicide attackers seized U.S. passenger jets and crashed them into two New York skyscrapers, killing thousands of people.

Four planes flying over the eastern US were seized simultaneously by small teams of hijackers. They were then used as giant, guided missiles to crash into landmark buildings in New York and Washington.

Two planes struck the Twin Towers of the World Trade Center in New York.

The first hit the North Tower at 08:46 Eastern Time (13:46 GMT). The second crashed into the South Tower at 09:03. The buildings were set on fire, trapping people on the upper floors, and wreathing the city in smoke. In less than two hours, both 110-storey towers collapsed in massive clouds of dust.

At 09:37 the third plane destroyed the western face of the Pentagon - the giant headquarters of the US military just outside the nation’s capital, Washington DC.

The fourth plane crashed in a field in Pennsylvania at 10:03 after passengers fought back. It is thought the hijackers had meant to attack the Capitol Building in Washington DC.

The attack remains one of the most traumatic events of the century, not only for Americans but also for the world.

-with inputs from BBC