"At this preliminary point in the investigation, there is no information that suggests the crash was intentional," the Massachusetts State Police said in a statement.
Local media, citing unnamed sources, said the taxi driver may have hit the gas instead of the brake pedal. Police said they were interviewing the driver, a 56-year-old man from Cambridge, Massachusetts.
Boston police officers, as well as fire and emergency services personnel, were on the scene of the crash, which occurred in the city's East Boston section, the Massachusetts State Police said in a Twitter post.
"Preliminary reports indicate several pedestrians with injuries, varying severity," the police said.
At least 10 people were taken to hospitals after the crash, Boston Emergency Medical Services said in a Twitter message.
Video footage on CNN showed what appeared to be a taxi, with its front hood buckled, resting next to a building.
The people who were hit were on a patio next to the parking lot where dozens of taxis were parked, WCVB-TV reported.
Thumbnail Credit: Flickr: User, Tony Webster