Injured subway passenger is escorted away from Edgware Road Tube Station in London following an explosion Thursday. [AP]

Injured subway passenger is escorted away from Edgware Road Tube Station in London following an explosion Thursday. [AP]

Moments of jubilation has turned into shock and then indignation as Britons experienced a sudden turn of feelings in a matter of just one day.

Barely 10 hours after Britain's successful bid of the 2012 Olympics Games, the elated mood cut short in London on Thursday in the aftermath of deadly attacks against the public transport system of London, the country's world-class financial hub.

Latest reports put the number of deaths at least 33 as a result of seven blasts scattered across downtown London during the rush hour, with more than 185 people injured and the city's transport system plunged into a total chaos.

Scotland Yard said explosions were reported at Edgware Road, King's Cross, Liverpool Street, Russell Square, Aldgate East and Moorgate. The police confirmed that the deaths occurred at central London's Aldgate East underground station as the result of an explosion there.

Besides the blasts in the capital's underground system, a double-decker bus was also hit near Russell Square close to King's Cross train terminal, where several railways and highways interlaps.

Witnesses saw horrified people streaming out of underground stations, some of them wearing clothes stained with blood and scratched to shreds.

Ambulances and fire engines rushed to the explosion sites where police had evacuated passengers and cordoned off the areas. Some contingent teams were also reportedly sent to the streets to guard against any further attacks. Major hospitals in London are busy treating people injured in the explosions.

A somber-looking Prime Minister Tony Blair, speaking in Gleneagles, Scotland at a G-8 summit, condemned the attacks as "barbaric" and said that terrorists were behind them.

"It is reasonably clear that there has been a series of terrorist attacks in London," Blair said. "There are obviously casualties, both people that have died and people that are seriously injured."

Shortly after delivering the speech to his fellow countrymen, Blair left the G-8 summit by helicopter for London to oversee the emergency.

In London, Police chief Sir Ian Blair said there had been "many casualties" but it was too early to put a figure to those killed or injured. Appearing on BBC's television network, he urged people to be as calm as possible and stay where they were.

The attacks in London, nerve center of the finance world, have sent jitters across Europe, pulling down share prices in bourses in Germany, Paris and elsewhere in Europe.

The FTSE 100 index of leading British shares fell nearly four percent by late morning and late recovered some of the losses by early afternoon but was still more than two percent lower.

Gold prices surged more than one percent and safer currencies like Swiss Franc also gained while the British pound bore the brunt of the blow to fall to a 19-month low of 1.7430 dollars and a one-month low against the euro.