Artur Lebedev, Associated Press
LONDON — With more than 30 marathons this weekend and big events on the horizon, officials around the world are looking at security efforts in the wake of the fatal bomb blasts that shook Boston's race.
Britain was making last-minute efforts to tighten measures for former Prime Minister Margaret Thatcher's funeral on Wednesday at St. Paul's Cathedral, which is to be attended by hundreds of diplomats and dignitaries, including Queen Elizabeth II.
Police with bomb-sniffing dogs were seen Tuesday afternoon around such landmarks as Big Ben, the Houses of Parliament and Trafalgar Square ahead of the Thatcher funeral, but officials said the searches were routine and unrelated to the Boston attacks.
Near the Pentagon's subway station in Washington, D.C., meanwhile, two military personnel toting guns and a security official in a bullet-proof vest were spotted by one of the station's entrances.
Bomb-sniffing dogs and security officers were also deployed Tuesday to Chicago's Union Station.
Amtrak spokesman Marc Magliari said security had been beefed up at all its railway stations.
"No matter how many days, months or years pass without a major terrorist attack, it only takes one such attack to bring us back to the cruel reality," Interpol chief Ron Noble told The Associated Press early Tuesday, saying police around the globe would be on high alert.
Although security has been increased at some U.S. and European landmarks, overall terror threat levels have remained unchanged — in contrast to other recent bombings and thwarted attacks in which terror threat levels were raised and travel warnings put in place.
Such warnings have been issued in the past when threats are considered imminent and with potential international links.
Threat levels also remained unchanged at U.S. defense installations at home and abroad, according to a Pentagon spokesman who requested anonymity because he was not authorized to speak to the press about security.
"The (Boston) attacks mean that we will be assessing our security protocols," said a British security official who spoke on condition of anonymity because he is not authorized to be publicly named. "There is some initial information coming out ... but it is too early to draw any conclusions. There doesn't appear at this point, however, to be a wider threat."
Security would be particularly tight for the big events in Britain, which has been at the heart of several terror attacks in the past decade, including suicide bombings in 2005 that killed 52 people. Several international terror plots have also been traced back to suspects in Britain.
Workers are inspecting some of the country's 4.3 million CCTV cameras in high-traffic areas around London to ensure views are unobstructed and equipment is functioning. Workers in an underground bunker monitor the footage around the clock.
Boosting security may also include adding manpower, increasing air visibility and securing public transport routes. Police and counter-terrorism officials are also aggressively monitoring potential suspects.
More than 37,000 runners will be at Sunday's London Marathon, which will be attended by Prince Harry. Other marathons are also being held across the world this weekend in countries across Europe, in Japan, South Africa and around the United States.
London Marathon officials said the race would go on as planned but security was being evaluated. In Serbia, officials said they would raise their guard for the race.
"We will do our best so that this year the security level is even higher," said Dejan Nikolic, the organizer of Sunday's Belgrade Marathon.
Police in Linz, Austria's third largest city, said security was being tightened for the city's marathon Sunday, with police closely checking key points along the race, particularly the finish-line area.
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