NEWARK, N.J. (AP) -- A fire captain and two firefighters were injured while battling a blaze in two buildings in New Jersey's largest city.

Newark police say the fire captain was injured by falling debris inside one of the buildings on Sherman Avenue Wednesday.

The captain was taken to a hospital with injuries that are not considered life-threatening.

Two firefighters also were treated for minor injuries. Approximately 70 firefighters responded to the three-alarm fire, Newark Public Safety Director Anthony Ambrose said.

Police say the fire began in an unoccupied building and spread to a three-family structure.

The cause is under investigation.