NORTH ANDOVER, MASS. >> Authorities say an explosion at a Dow Chemical plant in northeastern Massachusetts critically injured four people and damaged the building.

Firefighters, paramedics and police responded to the plant in North Andover at about 2:30 p.m. Thursday.

Lawrence General Hospital officials say four people with shrapnel and burn injuries were brought to the hospital in critical condition. Three of the victims were later transferred to hospitals in Boston.

North Andover Town Manager Andrew Maylor says no chemicals were released into the air and there is no danger to the surrounding area.

The cause of the blast is under investigation. Local, state and federal authorities are at the scene.

A Dow Chemical spokeswoman didn't return a message Thursday.

A worker was killed in a chemical explosion at the same plant in 2013.