»Terrorist attack in the middle of London«

A number of people have been killed in a series of explosions on London's transport system during this morning's rush hour, causing chaos in the British capital, police and transport officials said.

Several blasts hit the Underground network and police said there had been at least three explosions on buses in the city.

A source at the Metronet consortium that runs part of the capital's Underground network said "there were three explosions and there have been some fatalities".

Home Secretary Charles Clarke said the blasts had caused "terrible injuries" although he did not give specific figures.

"I want to express sympathy on behalf of the whole government to the families and friends of those who have been injured," Mr Clarke told reporters outside Prime Minister Tony Blair's Downing Street residence.

"The health services are in support to deal with the terrible injuries that there have been."

The causes of the incidents, a day after London was awarded the 2012 Olympics and as leaders of the Group of Eight rich nations met in Scotland, were unknown but police said many of the city's Underground stations were affected.

"It is too too early to state what has happened," a London police spokesman said.

"I cannot comment on reports of bombs, but we have had multi-reports of explosions around London."

Underground

People were seen streaming out of one Underground station covered in blood and soot.

Passengers were evacuated from stations across the capital, many in shock and with their clothes ripped to shreds, witnesses said.

The entire system was shut down and major thoroughfares were blocked off by police and ambulance services.

Bus blast

One bus was blown up in Tavistock Square in central London, a policeman told Reuters.

"There have been some casualties and this has been declared as a major incident," a spokeswoman for London's Metropolitan Police said.

Virginia Crompton was close to the explosion on a double decker bus in Tavistock Square.

"I decided given the scale of the chaos, it was best to walk to work and head towards town, I've just gone through Russel Square and turned onto Gordon Square where I heard a huge explosion very close by," she said.

"I turned into Gordon Square Gardens which is where I am now and two men run past me who had witnessed what they said was a bus being blown up, they described the roof coming out and I said, 'do you think anyone was hurt' and they said 'yes, definitely'."

Aldgate East station

Emergency services rushed to the Aldgate East underground station where police reported the first incident at 8:59am local time.

"There were people streaming out of Aldgate station covered in blood," 27-year-old Kate Heywood said, on her way to work.

"There are shards of glass there, it is chaos," she said.

A Reuters correspondent at Oxford Circus station, at the heart of the underground system, heard an announcement over the public-address system saying: "A power outage has occurred London-wide. All train services are suspended."

A station official said: "All the power has gone down. I don't know when it'll come back."

Steve Spence was travelling on one of the trains.

"I was on an outer circle train - going from Paddington from Edgware Road ... there was a big flash, a loud bang and lots of smoke, and there was a train on the other track - it had stopped as well, lots of screaming," he said.

"When we evacuated the train the front of my train was smashed up and there was lots of debris from the other train on the track."

Police cordon

Police sealed off large areas around other underground and mainline rail stations.

Firemen donned chemical protection suits before rushing into stations.

Half a dozen people dishevelled and with soot-blackened faces sat on the floor at Russell Square Underground station or stood in shock as police cordoned off the area and ambulances crews raced in, one witness said.

The Great Eastern Hotel, which was hosting a conference on the Israeli economy, was evacuated. Israeli Finance Minister Benjamin Netanyahu was due to attend the conference but had not arrived.

The president of the European Parliament said that London had suffered a "coordinated series of attacks" and blamed terrorism for the blasts on public transport, which he said caused many deaths.

In a solemn statement to the assembly, which had interrupted its normal business, Josep Borrell said: "Reports have reached me of what now appears to be a coordinated series of attacks on London's transport system".

"Explosions have been detonated on three buses and four tube stations and there are already confirmed deaths and terrible injuries on a lot of people," he said.

"We have to deal with a lot of deaths."

The EU legislature observed a minute's silence after Mr Borrell said: "We all stand with you today, British people, and we will never let atrocities or terrorism defeat the values of peace and democracy."

The European Union's commissioner for justice and security affairs, Franco Frattini, also said the blasts that hit London's Underground and bus services were terrorist attacks.

"We have the tragic confirmation that terrorism has once again hit the heart of Europe and hit a country that holds the presidency of the (European) Union and the G8," Mr Frattini told reporters on the sidelines of a conference in Rome.

"What should we do? Activate immediately coordination between intelligence and police and offer the United Kingdom all the help it needs," he said.