Somebody was running around Back Bay alleys lighting trash on fire, might be to blame for fire in Beacon Street building

Somebody who spent Sunday night setting trash and Christmas trees on fire in Back Bay alleys may have sparked what turned into a two-alarm fire at 295-297 Beacon St. at Exeter Street.

Firefighters and police were kept busy tonight trying to track down whoever was setting alleyway fires, first in the area of Massachusetts Avenue and Charlesgate East, then several blocks away, in alleys off between Clarendon and Exeter streets.

Around 10:15 p.m., one of the fires spread into the walls of 295-297 Beacon St. and then into the basement and up to the second floor. The fire was knocked down around 10:30 p.m.

The Boston Fire Department reports no injuries, but that nine residents were displaced. Damage was estimated at $150,000, and arson investigators, already in the neighborhood, were called to the scene.

A Public Works crew came in to remove discarded Christmas trees in one particular alley to keep them away from the arsonist's matches.

Last April, a man a man was arrested on charges he set a series of trash and dumpster fires in the Back Bay and Public Garden.