Officers have blocked the road at Hillside Street to stop people from entering the Blue Hills Reservation by Houghton’s Pond where the fire appears to be. About 100 firefighters battled what started as a one-to-two-acre fire about a half-mile into the woods near Houghton’s pond. Most left by dark last night for a small crew to monitor.

The brush fire was about 40 acres wide and only 10 percent contained Monday night, according to a spokesperson for the Massachusetts Department of Fire Services.

A new brush fire has developed in the Blue Hills State Reservation, sending smoke into surrounding Massachusetts communities.