Fears of a terrorist attack evaporated yesterday as polling places across the United States reported no serious election-related trouble. Only a handful of localities stationed police officers or other security teams at or near polling sites.

From Philadelphia to Miami to Milwaukee to Las Vegas, dozens of polling places visited by reporters yesterday revealed no visible law enforcement presence and little concern about strikes by al Qaeda or other terrorists.

Across the Washington region, local police and federal law enforcement officials said they had not observed any significant activity related to the election.

"It's a very, very quiet day," said John G. Perren, assistant special agent in charge of counterterrorism operations at the FBI's Washington field office. Members of the area's Joint Terrorism Task Force investigated reports of several suspicious packages, but they turned out not to be dangerous, he said.

Homeland Security officials had raised fears that al Qaeda might try to disrupt U.S. elections after its March 11 attack on commuter trains in Madrid helped bring down the Spanish government.

"One of our top priorities is to ensure that our election process, which is one of our most important freedoms, won't become a target for terrorists," Brian Roehrkasse, spokesman for the Department of Homeland Security, said in July.

But retired Marine Brig. Gen. Matthew E. Broderick, director of the national Homeland Security Operations Center, said there were few reports of suspicious activity related to the election.

In one incident yesterday morning, New Jersey police reported the discovery of a white substance at a Burlington County polling site. "We worry about whether that will be anthrax or ricin," Broderick said. "But it turned out to be table salt."

The Homeland Security Operations Center also received a report that California law enforcement officials were investigating a report of a Middle Eastern man who photographed a fire station that was serving as a polling place. "I think it's just coincidental," Broderick said. "But you don't know, and you have to run it down."

The lack of a visible police presence in and around polling places nationwide was in part the result of a consensus reached in recent months by state election and law enforcement officials in 50-state teleconferences arranged by the National Governors Association (NGA), election experts said.

In briefings over the past several months, FBI and Homeland Security Department officials told state government officials that despite intelligence suggesting that al Qaeda would like to disrupt the U.S. electoral process, no information had emerged showing that terrorists were targeting Election Day or polling places specifically.

George Foresman, Virginia's top homeland security official, coordinated a series of telephone briefings in recent months that brought together federal and state officials assigned to balance polling site security concerns with the desire to avoid scaring away voters.

"It's a phenomenally delicate balancing act, figuring out how to preserve the core values of democracy while paying attention to security concerns," said Foresman, who was given the job by his boss, Virginia Gov. Mark R. Warner, chairman of the NGA.

During the summer, some states and counties across the nation considered stationing armed security squads at or near polling places. But in almost all cases, those officials were talked out of it, election specialists said. Foresman said one rural state considered calling up National Guard troops to protect all its polling places. "They had to peel me off the ceiling," he said, adding that the state soon backed off the plan.

One of the few jurisdictions to assign police near polling places was Chesterfield County, Va., a suburb of Richmond. The American Civil Liberties Union protested the move in a letter to county officials. Jean Jensen, executive secretary of the Virginia elections board, said the Justice Department sent observers to Chesterfield to check for signs that voters might feel intimidated.

Officials said the officers directed traffic, assisted with medical emergencies, and in one case helped a disabled veteran into a polling place. "We weren't really intimidating too much there,'' said Lt. Col. Andy Scruggs, deputy chief of operations for Chesterfield County Police. "We think it went extremely well.''

D.C. Police Cmdr. Cathy Lanier, who heads the Special Operations Division, said yesterday that voting went smoothly at the city's 142 polling places. Police responded to six reports of suspicious packages near polling places that turned out to be unfounded, Lanier said.

City police officials ordered beefed-up police patrols near polling places and put many of the department's 3,800 officers on 12-hour shifts. In a few cases, officers stood outside polls before election officials asked police to remove them.

In New York, police were stationed outside the approximately 3,000 polling sites, as they have been in previous elections, to prevent campaigning too close to the polls, officials said.

A police car sits outside St. Margaret's Episcopal Church in Dupont Circle as voters line up. The District ordered beefed-up patrols at polling places. Officer Cedric Hawkins keeps watch at Stuart-Hobson Middle School on Capitol Hill. Police were later withdrawn at election officials' request.