BOSTON (AP) -- Gov. Mitt Romney raised the security level on Boston's transit system Thursday following the rush-hour terrorist attacks in London that killed dozens of people and injured hundreds.
Romney said there was no specific intelligence about any threat to Boston or the Massachusetts Bay Transportation Authority system.
The governor said he raised the alert at 6:15 a.m., nearly 90 minutes before the U.S. Homeland Security Department asked authorities in Boston, Miami, Atlanta, Washington and New York to increase their vigilance over buses and trains. The federal government later issued a ''Code Orange'' alert for all the nation's mass transit systems.
''It did not take a rocket scientist to figure out that if there were going to be a copycat or coordinated activity in this country, that our subway system could potentially be threatened,'' Romney said.
His spokesman, Eric Fehrnstrom, said it is the first time such an alert has been issued by state officials, though federal Orange alerts have led to increased security on the regional transit system, notably after the Madrid train bombings last year.
Four explosions rocked the London subway system and tore apart a packed double-decker bus on Thursday morning. Officials reported at least 40 people were killed and hundreds injured. A group calling itself ''The Secret Organization of al-Qaida in Europe'' claimed responsibility.
Locally, the precautions include increasing the number of transit police officers and MBTA personnel on duty, with state police and federal agencies also putting officers in transit stations. All rail yards and bus depots have also been secured and passengers will be subject to inspections or searches when there is a reasonable level of suspicion, Romney said.
Boston Mayor Thomas Menino said the city was taking no extra security precautions beyond assisting the MBTA.
''It just reinforces the message that our world has changed since 9/11,'' he said. ''When events like this happen, we've got to be ready for it.''
The U.S. Coast Guard increased the number and frequency of its patrols of Boston Harbor, Petty Officer Lisa Hennings said.
The Massachusetts Port Authority warned passengers to expect an increased law enforcement presence and heightened security at Logan International Airport. Two flights that took off from Logan were hijacked during the Sept. 11 terrorist attacks and flown into the towers of New York's World Trade Center.
MBTA spokesman Joe Pesaturo said trains and buses would continue to operate on their usual schedules, and all stations would remain open. Transit workers have a standard operating procedure to follow when security is heightened, he said.
Commuter Jay Hanley, 36, of Cambridge, was riding on an MBTA bus when he learned of the London attacks through his handheld computer.
''It made me a little nervous at first, he said. ''I wasn't sure if it would be a coordinated thing an something would happen here too.''
An announcement telling people to report suspicious activity played repeatedly over the intercom as morning commuters hustled through the busy downtown Park Street subway station.
''You kind of hold your breath until rush hour is over because of the timing of the one in London,'' said Paul Dullea, a 37-year-old employee of the Boston Bar Association who rode the commuter rail and subway into Boston from his home in Millis.
At the North Station Commuter Rail hub in downtown Boston, a U.S. Immigration and Customs Enforcement agent was on hand with a dog, along with transit and local police officers.
''I've got that strange suspended feeling that a lot of Americans have, that until it's going on (here), until someone starts blowing up my subway, it still feels like it's somewhere else in the world,'' William Orem, a 39-year-old editor for a Boston publishing company, said in the Park Street station. ''If I stop to think about that, I know that's wrong.''