Heavily armed police manned checkpoints on streets around the U.S. Capitol and closed one avenue Tuesday, angering local officials who warned of turning the city into an armed camp hostile to tourists and commerce.

The new security measures, approved by congressional leaders, were imposed after federal officials announced that over the past several years terrorists had been closely monitoring major financial institutions in New York City, Newark, N.J., and Washington.

Police stopped cars at more than a dozen hastily erected Jersey barriers alongitol complex. Most cars were waved on after officers glimpsed inside, but during the morning rush hour cars were lined up for blocks along Constitution, which normally flows smoothly at this time of year when Congress is gone and many who work on Capitol Hill are on vacation.

Vehicles also were being inspected at checkpoints around the World Bank and International Monetary Fund buildings in downtown Washington, both named as buildings under surveillance by terrorists.

Capitol Hill Police Chief Terrance Gainer encouraged people to take public transpiration or seek alternative routes.

But District of Columbia Mayor Anthony Williams, standing on newly blocked-off 1st Street, which links the Capitol with Union Station several blocks away, said Gainer and other security officials had come up with an "unworkable and unacceptable" solution to the terrorist threat.

"This is a living, breathing city. You can't continue to close streets without doing death to commerce in this city, to tourism in this city, to the tax base in this city," Williams said.

"You're going to have traffic backed up to Delaware."

Eleanor Holmes Norton, Washington's nonvoting delegate in the House, complained that the decision was made by the Capitol's security officials, largely Gainer and the House and Senate sergeants at arms, without consulting officials of the capital city. "They did the easiest thing for them," she said, speaking of the new travel restrictions. "They forgot that we live here."

Norton and others said that even before Sunday's announcement security officials had been urging the closure of 1st Street. Senate aides said the plan was expedited with Sunday's revelations of a possible terror threat.

They said Senate leaders, including Sen. Trent Lott, R-Miss., chairman of the Rules Committee, which oversees security matters, signed off on the measures at the recommendation of the security officials.

Senate Majority Leader Bill Frist, R-Tenn., and Democratic leader Tom Daschle, D-S.D., made the announcement Monday about the measures, saying they would "help protect all those who work in, visit or drive by the Capitol."

The four-lane 1st Street runs between the Russell and Dirksen Senate office buildings. "We are very concerned about the improvised vehicle-borne explosive devices that have been used around the world," Gainer said.

The streets running between the House office buildings on the other side of the Capitol were closed to traffic soon after the Sept. 11, 2001, attacks.

Retractable barriers block all entrances to the Capitol grounds. Tourists can now visit the Capitol only in organized tours.