LONDON -- With security forces in many cities on alert for copycat attacks after the Boston Marathon bombings, British officials on Tuesday urged a review of security measures for the London Marathon on Sunday -- the next big international race -- as the police and military here prepared to deploy for another major public event with the ceremonial funeral of former Prime Minister Margaret Thatcher on Wednesday.
The French authorities also ordered security forces to reinforce patrols in public places "without delay," urging citizens to be on the alert for suspicious-looking packages or abandoned baggage but to avoid panicky reactions. In Berlin, the interior minister, Hans-Peter Friedrich, said German security officials were in constant contact with their American counterparts, but the Boston attacks would not change Germany's current assessment of a "critical" level of the threat from terrorism.
"The security and threat situation has not changed for many years," he said. Organizers of the Hamburg Marathon, also set for Sunday, said 400 police officers would be on duty guarding the 15,300 runners or diverting traffic. "At the moment there is no cause to change anything," said Frank Thaleiser, the head of the organizing body.
But Mark Milde, the race director of the Berlin Marathon to be held in September, said organizers would review security arrangements and the Boston bombs "will be forever in the back of our minds." Even the 600 police officers assigned to patrol the event would have to improvise in the event of a similar attack in Berlin, he said. "You never know where something's going to happen," Mr. Milde added in a television interview. "We're prepared for the worst, but of course you can't secure an entire 42-kilometer route."
In London, both the funeral and the marathon are likely to bring crowds of people onto the streets, as the Boston event did on Monday when two bombs near the finish line killed at least three people and wounded scores.
There had already been concerns that radical foes of Mrs. Thatcher's wrenching, market-driven social and economic changes would seek to disrupt her funeral, during which her coffin is to be borne on a horse drawn gun-carriage through central London along a route lined by 700 military personnel leading to St. Paul's Cathedral. Some of the city's most important thoroughfares, including Whitehall, Trafalgar Square, The Strand and Fleet Street, are to be closed to traffic from early morning until midafternoon.
Queen Elizabeth II and Prince Philip are to attend the ceremony along with hundreds of dignitaries, including former Vice President Dick Cheney and former Secretary of State Henry A. Kissinger.
As a mark of respect, lawmakers have ordered the chimes of Big Ben to be silenced during the funeral, while artillery rounds boom from the Tower of London as the funeral procession moves toward St. Paul's with a mounted escort of nine police officers on black horses.
Draped in the Union flag, Mrs. Thatcher's coffin was transported in a hearse on Tuesday to Parliament, where it will remain overnight in the 13th-century Chapel of St. Mary Undercroft in preparation for Wednesday's funeral.
British news reports said officials were debating whether the most likely threat to the ceremonial occasion came from disruption by domestic protesters or from terrorists. Either way, said former Home Secretary John Reid, the calculation would be that "we will be more resilient than any terrorist in the long run."
Last year, the city girded itself against potential terrorist threats during the London Olympics and Paralympics, fearful of any effort to reprise the London bombings of July 2005.
"Everyone will have been appalled at the terrible events in Boston," Mr. Reid said in a radio interview. "While the culprits and motivation behind the U.S. terror attacks are still unclear, this will obviously entail a review of security arrangements for both Lady Thatcher's funeral and the London Marathon."
He continued, "In light of the awful attacks in Boston, they will require extra vigilance from everyone involved and it is also to be hoped that everyone recognizes the added responsibility of cooperating with the police and the authorities at both events."
The London Marathon is among the world's biggest and usually attracts hundreds of thousands of spectators. It starts in southeast London and ends on The Mall near Buckingham Palace, passing locations including the Houses of Parliament.
David Lowe, a specialist in security at sports events, told the BBC, "I think you are going to find a lot of surveillance on the crowds." Among spectators, "there could be people looking elsewhere for totally different reasons; I can imagine that the security will be stepped up."
He added, "We have the two events where we have got to make sure, certainly the security services and the police, have got to make sure it is as tight as possible."
But the sports minister, Hugh Robertson, said that the marathon should definitely go ahead and that he was "absolutely confident" it could be protected.
"These are balance of judgments, but we are absolutely confident here that we can keep the event safe and secure," he said. "I think this is one of those incidents where the best way to show solidarity with Boston is to continue and send a very clear message to those responsible."
Mayor Boris Johnson of London said that "given events in Boston, it's only prudent for the police and the organizers of Sunday's race to re-examine" security arrangements.
Nick Bitel, the chief executive of the London Marathon, echoed that sentiment, saying, "The London Marathon, in common with most sports events in the world, have got fairly detailed contingency plans which one hopes can deal with anything that occurs. But when something of this nature does happen, you obviously want to review them and see if changes need to be made."
Reporting was contributed by Stephen Castle from London, David Jolly from Paris, and Victor Homola and Chris Cottrell from Berlin.
This article originally appeared in The New York Times.