We've just seen the first war of the 21st century.
- President George W. Bush
A terrible, terrible tragedy has befallen my nation.
- Mr Colin Powell, US Secretary of State
We will hunt down and find those folks who committed this act.
- President Bush
The country's at war, but we don't have the co-ordinates of the enemy - yet.
- Prof Leon Fuerth, an ex-national security adviser to the former vice-president Al Gore
The United States has been the bulwark against the threat of terrorist anarchy in the world. We will be urging politicians to take the appropriate action in terms of their approach to Sinn FΘin/IRA.
- Mr Jeffrey Donaldson, UUP MP, speaking after the attack
I'm 69 but I can still run.
- A New York man fleeing the massive dust cloud as the first of the twin towers collapsed.
The world is evil.
- A fireman attending victims of the attack at the World Trade Centre.
Oh my God, people are jumping, Oh my God.
- Women watching people throwing themselves from the towers.
It was like a sonic boom.
- Mr Ulas Branch on the moment a plane slammed into the west side of the Pentagon.
I was walking up West Broadway and I looked up and saw this two engine commercial airliner. He was low and fast. I looked at a lady walking a dog next to me and I said to her that this guy was too low. Then I heard him go full throttle and he crashed in to the building. It was suicide. There was no engine spluttering.
- Mr Marco Ponti on seeing the first of the aircraft to hit New York.
This is the second Pearl Harbour. I don't think that I understate it.
- Senator Chuck Hagel, a Nebraska Republican.
God help them, God help them, God help them.
- Mr Yasser Arafat, Palestinian Authority president, on the victims of the assault.
The only issue at this stage and the most important international priority at the moment is to show solidarity with the American people and to seek out the perpetrators of these dastardly crimes and bring them to justice.
- The Minister for Foreign Affairs, Mr Cowen, on returning from the Middle East.
I feel I am in a dream. I never believed that one day the United States would come to pay a price for its support to Israel.
- Mustafa, a 24-year-old Palestinian living in the West Bank, on hearing of the attack.
No one understands this better than Israel. We have been on the front line of this for decades. But now terror has hit the heart of the free world.
- Former Israeli prime minister, Mr Benjamin Netanyahu.
We . . . here in Britain stand shoulder to shoulder with our American friends in this hour of tragedy and we, like them, will not rest until this evil is driven from our world.
- The British Prime Minister, Mr Blair.
I'm like every other human being with any scrap of human decency and any scrap of human compassion, I'm watching the pictures and it's absolutely unbearable.
- The President, Mrs McAleese.
This is one of those days in life that one can actually say will change everything.
- Mr Chris Patten, EU External Affairs Commissioner.
We're not only going to rebuild. We're going to come out stronger than we were before.
- Mr Rudolph Guiliani, Mayor of New York City
The America in which we woke today is far different from the one in which we woke yesterday.
- Mr Tom Daschle, US Senate Majority Leader
I'm a lovin' guy, but I won't relent.
- Mr Bush speaking to the press at the Oval Office