The Bush administration has raised the security-threat level for some forms of public transportation, while leaving the overall alert level unchanged for the nation as a whole. Department of Homeland Security Secretary Michael Chertoff held a news conference several hours after the London explosions.
Secretary Chertoff stressed that the United States has no specific, credible information that a terrorist attack is imminent on American soil, but said that certain measures are reasonable and prudent.
"In light of today's attacks in London, the United States government is raising the threat level from Code Yellow, 'elevated', to Code Orange, 'high', targeted only to the mass-transit portion of the transportation sector," he said. "This includes regional and inner city passenger rail, subways and metropolitan bus systems. We are also asking for increased vigilance throughout the transportation sector."
The color-coded security threat-level system was implemented in the wake of the September 11, 2001 terrorist attacks in the United States.
Mr. Chertoff said federal agencies, as well as state and local authorities, are working together to take necessary precautions and to boost security measures for the country's mass transit infrastructure.
He added that the Department of Homeland Security is in no way suggesting that Americans avoid public transportation.
"I think our transit systems are safe, and in the time period since 9/11 and in the time period since [last year's] Madrid [train bombing], we have worked with our partners in the Department of Transportation, with out state and local partners all across the country, to raise the level of everyday protection," he said. "And that includes [bomb] detection equipment, it includes police presence, it includes protocols."
In Washington, heavily armed security forces and canine teams have been combing the city's subway stations, while stop-and-inspect operations have been set up for vehicles traveling on certain roads near the U.S. Capitol. Washington Mayor Anthony Williams issued a request to his city's residents.
"To ask people to join with us to keep their eyes and ears open as they go about their daily business, and if they find anything unusual to alert our authorities," he said.
Speaking with reporters, New York Governor George Pataki expressed confidence that measures implemented to safeguard New York City's mass transit system would prove adequate.
"I am extremely confident that the law enforcement officials in the city and in this region, including the New York [City] Police Department, which is the finest police department anywhere in the world, are doing everything they can to make sure that the people who use our mass transit system, or just come to visit this great city, are as safe as they can possibly be," he said.
Meanwhile, several Muslim groups in the United States are condemning the London bombings. In a statement, the Washington-based Council on American-Islamic Relations said: "We join Americans of all faiths, and all people of conscience worldwide, in condemning these barbaric crimes that can never be justified or excused."
In California, the Islamic Relief charity organization said it "condemns categorically the terrorist attacks in London" and that "our hearts go out to the victims and their families."