CALAIS – A terrorist plot to attack the train tunnels beneath the Hudson River in New York may have been foiled hundreds of miles away, but some motorists trying to cross the border from Canada into the United States on Friday believe it had a ripple effect in Maine as they faced waits of more than an hour to enter the country.

Boston officials for U.S. Customs and Border Protection denied Friday that there was any stepped up security as a result of the alleged plot, although they did say that border guards remained vigilant.

“As far as our border goes we’ve always been vigilant in ensuring in stopping terrorists entering the country, but at the same time facilitating legitimate trade and travel,” Ted Woo, U.S. Customs and Border Protection public affairs officer, said Friday.

But waits at the border in Calais on Friday increased after news of the alleged plot broke that morning. According to The Associated Press, federal authorities apparently disrupted a plot by foreign terrorists to attack the train tunnels beneath the Hudson River that connect New York City with New Jersey,

Traffic delays lasted most of the day in Calais. “It’s terrible; I don’t know what kind of game they’re playing,” a New Brunswick driver said Friday evening.

A woman who said she lived in neighboring St. Stephen, New Brunswick, said she had been monitoring traffic all day. “It’s been tough all day,” she said.

Officials at the Madawaska and Houlton border crossings on Friday referred all questions to the Boston office, but afternoon traffic at the Houlton port of entry appeared to be flowing smoothly.

No information was available on the Madawaska crossing.

In Calais, two bridges, the downtown Ferry Point Bridge and the Milltown Bridge near the city’s Industrial Park, serve Calais. There were long waits at both border crossings.

While traffic was delayed, according to Woo, there was nothing out of the ordinary and it was business as usual for customs officials.

“From time to time people are going to be able to go through Calais or even at one of our international airports, they might have a little bit less scrutiny one time, but the next time they come in it may be a little more in depth.” Woo said. “It’s our way of keeping everybody honest. They may get a free pass one day, but then the next day be checked.”

Border guards were checking trunks and the inside of vehicles, something they hadn’t done for weeks.

And federal officers were asking to see drivers’ licenses or identification cards. They then keyboarded the person’s name and other information into a data system. Travelers who encountered an agent with limited typing skills sat and waited longer.

Woo said that the CBP does monitor traffic wait times. “Our managers up on the border are constantly checking the wait times and monitoring it seven days a week. The director of field operations here in Boston makes sure that we are not holding up legitimate trade and travel,” Woo said.

Woo said that even when the terrorists were arrested in Toronto last month it didn’t change border operations. In June, Canadian police stopped a planned terrorist attack by arresting 17 suspects. The men allegedly planned to storm Parliament and kill the Prime Minister. “We are always at a point where we are vigilant in our inspection of people coming into the country,” Woo said.

While drivers were waiting in line at the Calais border, some were listening to their radios. That was when they learned from The Associated Press and other news agencies that authorities apparently interrupted a plot by foreign terrorists to attack the train tunnels beneath the Hudson River. The tunnels are used daily by New York City commuters.

News of the plot emerged on the one-year anniversary of the attacks on the London transportation system that killed more than 50 people.

Maine’s two senators said they plan to look into this latest incident of delays at the Calais border.

“It is imperative that we balance our homeland security needs with economic needs of our border communities,” said U.S. Sen. Olympia Snowe on Friday afternoon. “I have learned that delays along the Canadian border have increased dramatically – indeed this increase could be a direct and necessary result of heightened security across the country. I will be looking into these delays to ensure that the wait times are reasonable and are not having an undue economic impact on the region.”

U.S. Sen. Susan Collins’ press spokesman Kevin Kelley said that the senator considered the border crossing in Calais an important port of entry and would contact customs officials to learn what caused the delays.