Thousands of Massachusetts Bay Transportation Authority passengers spilled into the streets by the Kenmore T station yesterday afternoon as a fire in the Boylston station halted inbound transportation on the B Line.

At around 3:45 p.m., MBTA employees announced to passengers in the station that service would not be available for an indefinite amount of time, instructing them to exit on the ground level, where alternate transportation was available. However, many employees said they were unaware of any details regarding the incident, including the fact that there was a fire at all.

Less than an hour after the fire started, MBTA spokeswoman Lydia Rivera said she had little information about what happened. She mentioned the fire had been started by “overhead wires,” and she said it was “undetermined” whether the fire was in the subway or in the station’s tunnels.

Outbound service on the Green Line continued at the Blandford Street T-stop, and the C and D Lines were still running. However, passengers traveling inbound had to board one of many shuttle buses traveling to Park Street.

Many passengers exiting the Kenmore Station said they were confused and unsure how to proceed despite the instructions of MBTA employees.

Jamilah Johnson, 15, was traveling from Brighton.

“They said there were difficulties, and we all had to get off,” she said.

Many MBTA employees working with the bus service said they were called into Kenmore without any explanation. Some found out about the fire, and that the Green Line had “broken down,” by listening to the radio in the booth outside the station’s entrance.

People entering the station after original announcements were made were turned away from inbound transportation inside the station, sometimes after paying for the trip and walking through the turnstiles.

In front of about six shuttle buses that crowded the street in front of Barnes ‘ Noble, an MBTA employee shouted to all the passengers waiting nearby. Muffled by street noises, he told the passengers about transportation alternatives. The employee, who requested anonymity because of an MBTA policy that prohibits workers from speaking to the press, said he was not bothered by disgruntled passengers who were harassing him.

“People just don’t understand — things happen,” he said. “They expect buses to show up, but it’s rush hour. It’s a question of hiring people for the extra work.”

Although frustrated by the inconvenience, some passengers said handling the crisis was a difficult job for the MBTA.

“What can they do?” Jenn Bean, a Brighton theater technician, said. “They just can’t handle the crowds.”

Tufts University Research Associate Tina Stancheva said the holdup took up a large part of her day.

“They can’t do anything about it,” she said. “[The employees] seem nice, but . . . it looks like they’re doing their best.”

Staff reporter Anita Davis contributed to this article.