North Stonington — Firefighters spent half the day battling a brush fire Tuesday that consumed nearly 4 acres of ground cover but was halted before reaching nearby homes.

North Stonington Fire Chief Charles Steinhart V said firefighters were called at 12:41 p.m. to the area of 378 Pendleton Hill Road for a report of the fire. Firefighters did not return to the station until after 6 p.m.

Along with brush, Steinhart said the dry conditions led to underground hot spots and a labor-intensive firefight that involved foam, water and tools to dig up the ground.

North Stonington received mutual aid from Griswold, Voluntown, Ashaway, R.I., Old Mystic and Wequetequock (Stonington) fire departments along with North Stonington Ambulance and a crew from the forestry division of the state Department of Energy and Environmental Protection.

Two firefighters sustained injuries, Steinhart said, including one treated at the scene for a heat-related condition and another taken to The Westerly Hospital for treatment of a hand injury.

The cause and origin of the fire remains under investigation.