Taking cues from recent terror attacks across the globe, city, state and federal officials said they plan to ramp up security at this weekend's Sail Boston event by increasing police presence, closing roads, setting up roadblocks and using heavy machine vehicles to block cars and trucks from entering areas where police predict a large number of spectators.

"There's certainly a heightened level of security," Gov. Charlie Baker said at a press conference Wednesday. "But that's not new."

Boston Mayor Marty Walsh said "all eyes" will be on the city of Boston as more than 50 Tall Ships from a dozen countries sail in for the first time since 2009. He expects some 2 million people from outside the city will flock to the waterfront over the course of the five-day event.

The FBI rated Sail Boston a SEAR 1 security threat. For comparison, the Boston Marathon is ranked a SEAR 2. The ranking is not due to a specific threat, officials said.

"We've seen the attacks in other cities around the world and we've taken a lot of the strategy they've used to hurt people and we've set up perimeters such as the trucks . . . We're watching all of the vulnerabilities other places might have had," Walsh said. "Boston's in a safe place. That doesn't mean that something can't happen. All that means is we have no threats today."

Baker added the addition of barriers to prevent large vehicles from coming near crowds represents an "amount of control" the city did not have when Sail Boston last happened in 2009.

Boston Police Commissioner William Evans said spectators will be required to pass through security checkpoints and should not bring items like backpacks or large coolers that could "slow down" the security process. Police may ask spectators to move from crowded locations, Evans said, to ensure no area becomes too populated for police to effectively patrol.

State Police Superintendent Col. Richard McKeon said uniformed and undercover state troopers will be on site, as well as K-9 units, a bomb squad and the state police air wing. Additional officers will work behind-the-scenes to gather intelligence, McKeon said. Walsh added that spectators should alert police of any suspicious activity, like an unattended backpack.

"If you see something out of the ordinary," Walsh said. "Just grab a public safety official. Rather be safe than sorry."

The Massachusetts Coast Guard will also "maintain a strong presence," according to Capt. Claudia Gelzer. Some 500 active duty Coast Guard service members and 100 members of the Coast Guard Reserve will be on duty during the event. Heightened security measures will include a 24/7 response team and three Coast Guard cutter ships, as well as a 25-yard safety zone around all moored Tall Ships. Officials did not say how many city and state police officers will be on duty. Evans said it will be a "significant" amount, but will not reduce resources in other city neighborhoods like Mattapan.

Because of road closures across East Boston, South Boston, Charlestown and downtown, officials stressed those who plan to attend Sail Boston should take public transportation and carefully review the event's website for places where they can watch the event. It is not likely that commuters will be impacted by the event on Monday morning, officials said.

Security is focused on the public, Walsh said, explaining that no additional safety precautions have been taken for elected officials following a shooting at a Congressional baseball practice in Virginia on Wednesday morning. Baker said he is concerned about those who were shot in the incident and added he is "pleased" that the Congressional baseball game will still be held. He said that game is one of few events in Washington that creates a "good feeling" for members of Congress on both sides of the aisle.

As far as costs go, Walsh said price of securing Sail Boston will not be known until after the event. Last month, the Massachusetts Convention Center Authority Board voted to spend $4.25 million to help, according to an MCCA spokesman, with $3.5 million earmarked for security.

The city expects Sail Boston will generate $120 million over five days.

[Matt Murphy contributed reporting]