A child was among four people injured in an extra-alarm blaze early Thursday in an Albany Park neighborhood apartment building on the Northwest Side.

Firefighters responded shortly after 1 a.m. to the blaze that started in the back of the three-story building in the 3800 block of West Montrose, according to the Chicago Fire Department. The fire was extinguished by 1:53 a.m.

Several people had to be rescued from the fire, fire officials said. Three adults and one child were taken in fair-to-serious condition to Swedish Covenant Hospital.

At least 12 people were displaced because of the fire and the American Red Cross was called to the scene to assist with housing, according to Chicago Fire Department Cmdr. Walter Schroeder.

The cause of the blaze was under investigation.