World leaders and other international figures have offered their sympathy and support after the bomb attacks in London, which have left at least 50 people dead and 700 injured.
Below are a selection of their reactions.
UN Secretary General Kofi Annan
I was devastated by the atrocious bombings that struck London today. These vicious acts have cut us all to the core, for they are an attack on humanity itself.
Today, the world stands shoulder to shoulder with the British people, who with others around the world had mobilised so powerfully against poverty and climate change ahead of the G8 summit, and who, I am sure, will confront this ordeal with the same spirit, courage and determination.
US President George W Bush
We will find [the perpetrators]. We will bring them to justice. And at the same time we will spread an ideology of hope and compassion that will overwhelm their ideology of hate...
You've got people here [at the G8 summit] who are working to alleviate poverty and to help rid the world of the pandemic of Aids. They're working on ways to have a clean environment and on the other hand you have people killing innocent people.
President Bush insisted the war on terror would continue
The contrast couldn't be clearer between the intentions and the hearts of those of us who care deeply about human rights and human liberty and those who kill.
French President Jacques Chirac
I would like to express the full horror I feel at the terrorist attacks which bathed the British capital in blood this morning. I would like to express to all Londoners, to all of the British people, the solidarity, the compassion and the friendship of France and the French people.
Afghan President Hamid Karzai
This is an attack not against a city, this is an attack not against a nation, this was an attack against the whole of mankind.
Mr Karzai is a key partner in the US-led war on terror
Iraqi Prime Minister Ibrahim al-Jaafari
It is a shameful terrorist act that doesn't have any relation to religions and human morals. While I am expressing my deep sorrow to you and through you to the British people and families of victims, I
confirm to you our deep will to rid the evil of terrorism in any country as it appears.
Israeli Foreign Minister Silvan Shalom
Israel, which has a long experience of terrorism, shares in the pain of the British people... I hope that the free world will now be less lax in its attitude towards terrorist organisations.
Iranian foreign ministry spokesman Hamid Reza Asefi
Iran [has] sympathy with the families of the victims of these terrorist acts [and denounces] the use of violence to achieve objectives.
Abdulmohsen al-Akkas, Saudi social affairs minister
It is a heinous act. I don't know who did it. I condemn it in the strongest possible terms and I offer my sympathies to the families.
US Secretary of State Condoleezza Rice
These terrorists attacked without warning on 11 September 2001. They have attacked in Madrid, in Jakarta, in Morocco.
This is a worldwide war against ideals. There is no separate peace to be made with terrorism.
Rice signed a condolences book at the British Embassy in Washington
They are after our way of life and we have to deal with them. There is no other way other than with strength.
European Commission President Jose Manuel Barroso
It's absurd, those criminal attacks against innocent people that have nothing to do with the problems that are raised by the terrorists. This criminal act [is] not only against Britain, against the British people, but against all civilised people in the world that do not tolerate these kind of crimes.
Australian Prime Minister John Howard
I express my horror and disgust at this cowardly attack on innocent people. These sorts of attacks will not alter the determination of free countries to do the right thing.
It's important that we stand shoulder to shoulder with our British allies at a time such as this.
Telegram on behalf of Pope Benedict XVI
Deeply saddened by the news of the terrorist attacks in central London, the Holy Father offers his fervent prayers for the victims and for all those who mourn.
While he deplores these barbaric acts against humanity, he asks you to convey to the families of the
injured his spiritual closeness at this time of grief.
Upon the people of Great Britain, he invokes the consolation that only God can give in such circumstances.
Russian President Vladimir Putin
The response to these inhumane crimes wherever they take place - be it London, New York, Moscow or other countries - should be absolute condemnation.
All civilised countries should unite in the fight against international terrorism.
Spanish PM Jose Luis Zapatero
Spain has suffered the scourge of terrorism for decades and on 11 March last year it was the victim of the most horrific attack recorded until then in Europe.
For that reason, we, the Spanish people, well understand the suffering that today the British people are undergoing.
Mr Zapatero recalled the attacks in Madrid in March 2004
We share their pain intensely, just as they and so many other peoples of the world did with us on other occasions.
Rudolph Giuliani, Mayor of New York on 11 September 2001
My heart goes out to the people who were affected by this, it reminds me so much of 11 September.
I feel very sorry for them and I offer all the support and help and assistance that we can give. I was right near Liverpool [Street] Station when the first bomb went off and was notified of it and it was just to me very eerie to be right there again when one of these attacks takes place.
These are dastardly cowardly acts and the best way to react to them is to stand up to them and do everything we can to support the people that were affected by it, but not to let these terrorists affect our way of life.
Nigerian President Olusegun Obasanjo
This is indeed unfortunate at this time when you [at the G8] are doing so
much to bring the world together.
Mr Prime Minister [Tony Blair], please do not despair. The world and all progressive humanity are with you. Terrorism in all its forms and ramifications must be exposed, resisted and defeated.
Sheikh Rashid, Pakistani Information Minister
We condemn the attacks in London this morning. We offer our heartfelt sympathies to those who suffered due to such acts.
Irish Prime Minister Bertie Ahern
This is terrorism and violence perpetrated against ordinary people. It's just a black mark on society, a devastating blow against people. This is a huge emergency. A terrible, sad day.
Javier Solana, EU foreign policy chief
A terrible event can happen at any time. We cannot let down our guard. We are working every day, and in a co-ordinated way in all the EU countries.
Unfortunately there are times when one cannot prevent one [an attack] happening.