Police officers carrying automatic weapons patrolled streets around the Capitol last night as they prepared to close a major thoroughfare on Capitol Hill and to set up 14 vehicle checkpoints, creating a huge security perimeter around powerful symbols of American democracy.

Amid objections from city leaders, U.S. Capitol Police Chief Terrance W. Gainer said last night that First Street NE between Constitution Avenue and D Street NE -- which runs between two of the Senate office buildings -- would be shut down indefinitely, starting this morning.

In addition, Gainer said Capitol police would set up checkpoints at several key spots around the Capitol and Supreme Court buildings, inspecting vehicles that cross Independence and Constitution avenues near Capitol Hill, as well as several other streets in the area.

D.C. police, meanwhile, said they would set up checkpoints near the World Bank and International Monetary Fund headquarters to scan traffic and pick out cars and trucks for inspection. Those checkpoints will be on 18th Street NW between F and G streets and on 19th Street NW near I Street, police officials said.

Squads of officers from different agencies patrolled the Foggy Bottom headquarters of the IMF and World Bank and the Capitol yesterday and concentrated bomb-sniffing dogs in the subway stations around Foggy Bottom and the White House. Workers tried to go about their business and ignore the threat.

The announcement by Capitol police came as some government officials acknowledged that most, if not all, of the al Qaeda surveillance that led to Sunday's new terror alert occurred about three years ago or possibly longer.

D.C. officials blasted the Capitol Hill action, saying the closure and checkpoints would lead to gridlock and send the wrong message to tourists and residents. Several pointed out that the Capitol and Supreme Court were not mentioned in the announcement Sunday by Homeland Security Secretary Tom Ridge that raised the threat level in the District, New York and Newark. Ridge singled out the financial districts in those locations, including the IMF and World Bank.

But Gainer said the threat level is increased across the city, not just at the financial centers.

"There has been ongoing concern about the Capitol," Gainer said. "The 9/11 Commission report indicated the great likelihood that the Capitol was a target. We see the intelligence that terrorists would like to strike the United States and the Capitol of the United States."

The Capitol Hill closure brought a swift and sharp rebuke from D.C. Mayor Anthony A. Williams (D), whose spokesman said city officials learned late yesterday that "the nervous nellies in Congress" were closing the street near the Capitol.

The spokesman, Tony Bullock, said the mayor and other D.C. officials would try to persuade security officials to reopen the street. City officials also are concerned that if Congress is permitted to close streets, other federal agencies could follow suit, as has happened in the past. "It scares people," Bullock said, referring to the security zone. "This is not Beirut."

Del. Eleanor Holmes Norton (D-D.C.) said she was outraged. "The arrogance of it is mind-boggling," said Norton, who has called a news conference this morning to discuss alternatives. "Closing down a main thoroughfare must be the last option, and it has become the first option here."

Gainer said he took the action after reanalyzing data about the effect a car or truck bomb would have on the Capitol, the House and Senate buildings and people in the area. Gainer said that he has also placed his officers on 12-hour shifts and required them to work six days a week. "We feel that a threat to one section of the city is a threat to all of the city," Gainer said.

He said his police force will also be carrying more automatic weapons and shotguns when they patrol the Capitol. He said he understood concerns about road congestion. "We will work with the city to alleviate the traffic as best we can," he said.

"It's tough," he said. "It's discombobulating. But I think the reaction is similar to what it would have been in August 2001 if we said we are going to screen everyone at the airport and there may be two-hour waiting lines."

Gainer's plan requires 300 officers to work six days a week and is expected to cost as much as $3 million a month in overtime. He said it would probably be in place until November and possibly beyond.

D.C. police also plan to ban street parking between F and H streets NW from 18th to 20th streets and from the south side of Pennsylvania Avenue in that area. Officials also are considering ways to limit the routes trucks can take into and through the District. D.C. Police Chief Charles H. Ramsey said the precautions probably would be in place through November.

At the World Bank and IMF, iconic financial institutions two blocks from the White House and across from each other on 19th Street NW, thousands who reported to work yesterday were checked by security guards.

Damian Milverton, a spokesman for the World Bank, said more than 1,200 employees attended a staff meeting at which World Bank President James D. Wolfensohn said they could expect increased security measures.

Milverton said Wolfensohn told employees that "the information that the U.S. authorities picked up was from 2001 and there was no evidence to suggest an imminent threat to the bank."

Cars trying to enter the underground parking garages at either high-rise building were lined up along G Street and searched by guards who inspected their trunks and used mirrors to check their undercarriages. One IMF worker who bicycled to work hopped off to let a guard peer into the bag on the back of her bike. D.C. police officers, some with bomb-sniffing dogs, patrolled virtually every corner.

Metro Transit Police focused on the three stations close to the World Bank and the IMF: Farragut West and Foggy Bottom on the Blue and Orange lines and Farragut North on the Red Line. A special unit of transit officers with automatic weapons was dispatched to the area, and police dogs roamed the stations.

Still, the streets surrounding the World Bank and IMF appeared just as busy with vehicle and pedestrian traffic as on any other August workday. Employees at a few shops near the IMF and World Bank said business was booming. A bank spokesman said that employee turnout was typical, although no official tally was available. And office and blue-collar workers in and around the Foggy Bottom buildings said they were not afraid, in part because of a heavy police presence and nerves hardened by three years of terror warnings.

The terror threat did not stop office workers from enjoying lunch on benches in a small park across Pennsylvania Avenue and H Street from the World Bank. "I was actually more worried about traffic than anything," said Patrick McDonough, 31, who works at a nearby medical services provider and was eating with a colleague in the park.

Arthur Foy didn't think twice about making a delivery just a few dozen paces from a potential terrorist target. Duty -- and a truck full of pre-cut french fries -- beckoned.

"I'm more concerned about the weather than the terrorists, to be honest," said Foy, 53, a shorts-clad, sweat-drenched worker for U.S. Foodservice, as he unloaded boxes from a truck parked at 18th and H streets.

Staff writers Michael Barbaro, Karin Brulliard, Cameron W. Barr, Sari Horwitz, Theola Labbe, Allan Lengel, Lori Montgomery, Matthew Mosk, Monte Reel, Ian Shapira, Michael D. Shear, David Snyder, Martin Weil and Del Quentin Wilber contributed to this report.

Ray Bond, a heavily armed Metro Transit Police officer, rides a train on the Orange Line. Police focused patrols on the three stations close to the World Bank and IMF.

D.C. police officer Abner Joge, right, searches the Steel Office Interiors truck driven by Marty Finley, left. Officer Neil Morgon stands in the middle of 19th Street NW ready to flag down other large vehicles near the World Bank building.A sign warns motorists traveling near the Capitol that they will be subject to checkpoints as part of the stepped-up security.

Officer H. Fearnow of the Metro police stands guard outside the Farragut West stop near the IMF and World Bank.