"In the face of these odious acts, I want to express my most profound solidarity, my friendship and my support to all the British people, and particularly those living in London," French Prime Minister Dominique de Villepin said in a televised statement shortly after the bombings.

In a message sent to the Catholic Archbishop of Westminster Cardinal Murphy O'Connor, Pope Benedict XVI deplored what he called "these anti-human and anti-Christian acts."

From Madrid -- scene of similar multiple terrorist attacks on commuter trains on March 11, 2004, -- Prime Minister Jose Luis Rodriguez Zapatero condemned the "brutal actions," and sent a message of sympathy and support from the Spanish people to Prime Minister Tony Blair.

"The terrorists will never force us to abandon our principles and values," Zapatero said in a defiant televised statement. "The moral force of democracy is stronger than their vile and cowardly methods. Terror will never impose itself on the rule of law and on democracy."

Meanwhile, in a gesture of solidarity with Britain, Spain's King Juan Carlos I ordered the cancellation of Thursday's annual graduation ceremony at the San Fernando Military Academy in the west coast port of Cadiz.

At the margins of the G-8 summit in Gleneagles, Scotland, French President Jacques Chirac denounced the attacks as unconscionable. "The scorn in which the human life is viewed is something which together we must fight against with increasing firmness, with solidarity among the great nations of the world against those who commit [the terrorism]," Chirac said in televised remarks.

In Strasbourg, the European Parliament held a minute's silence for the victims of the London attack; and the EU commissioner for justice, Franco Frattini, said the London bombings were "an attack directed against Europe, not just the United Kingdom."

Amr Moussa, secretary general of the Cairo-based Arab League, said the Arab organization "expressed its profound regret and condemned the (London) attacks."

The bombing outrage put something of a damper on London's triumph at winning the Summer Olympics bid Wednesday. The head of the bid team, Keith Mills, announced that celebrations planned for later in the day had been cancelled. But in Singapore the President of the Olympic Committee Jacques Regge discounted that the terrorist attack was linked to London's successful bid. "Attacks like this one simply can't be organized in a short time," Regge said. "Cities like London, Paris, and New York are constantly at risk. There's no such thing as an oasis of security."

France has raised its security alert from orange to its highest level, red. De Villepin, who spoke minutes after hosting an emergency cabinet meeting, said he had asked his ministers for suggestions on beefing up security at the country's most vulnerable sites.

The French foreign ministry has put in place a public information number following the London blasts (01-45-50-34-60 or 33-1-45-50-34-60 for those calling outside France).

An Internet statement reportedly attributed to "The Secret Organization of al-Qaida in Europe" that has claimed responsibility for the attacks in retaliation for Britain's roles in the wars in Afghanistan and Iraq, also threatened to stage similar attacks against Italy and Denmark for their own involvement in both countries.

In Paris, metro traffic was disrupted midday on the Line 4 line running north-to-south across the city, after a suspect package was found on a train.

France and Britain were split bitterly over the war in Iraq, with Paris leading international opposition against the U.S.-led conflict. But Thursday, French-British differences over Iraq and a host of other subjects -- notably French ire over losing its bid to host the Olympics games -- were fading rapidly.

On Wednesday, French newspapers were filled with bitter comments about London's lack of fair play and the city's aggressive lobbying for the Olympic prize. Rejection of the bid from Paris -- the favorite -- was "a slap," wrote the conservative Figaro newspaper. On Thursday the tone had changed. "The attacks have ruined London's triumph," Le Monde wrote. They mark, the newspaper added, "the return of terrorism in Europe."