PORTLAND, Maine — Two children playing with sparklers caused a two-alarm fire Monday morning that led to the evacuation of a 22-unit apartment building and the blocking off of a section of Congress Street.

There were no reported serious injuries as a result of the fire, although one firefighter was taken to a local hospital for evaluation.

Damage from the flames and smoke has displaced the residents of seven apartments. The Portland Fire Department is working with the American Red Cross to secure relief and shelter for the nine people displaced, according to a press release.

Wendy Townsend, 30, lives in an apartment above and one unit over from the apartment in which the fire began. Townsend said she was in her third-floor apartment around noon when a fire alarm began to ring and her boyfriend noticed smoke coming out of their ceiling. She said despite many false alarms in the building, they knew this was the real thing.

“I was going down the stairs and I couldn’t breathe,” she said.

The Portland Fire Department found that children in a second-floor apartment of 8 Montgomery St. accidentally set fire to a mattress after using a toaster to light morning glories, a type of sparkler which is legal in Portland and sold widely at gas stations and convenience stores.

The block of Congress Street between Montgomery Street and Washington Avenue was closed to foot and vehicle traffic early Monday afternoon. Deputy Fire Chief David Jackson said between 38 and 45 firefighters responded to the fire alarm and the fire was extinguished shortly after their arrival at the building.

Jackson said he could see black smoke billowing from the building as he approached shortly before noon.

Rainer Maas, 60, who lives in a building on the corner of Congress Street and Washington Avenue, said he saw flames leaping from the back of the building in which the fire occurred.

“We were looking from our kitchen on the fourth floor, and the Fire Department was already here,” Maas said. “We watched for a while and there was a lot of dark smoke coming out.”

The sale and use of fireworks is illegal in Portland, although sparklers are legal. This is the second fire in Portland in three days involving fireworks. Firefighters responded Saturday afternoon to a Dumpster fire ignited by fireworks at the Hall School.

The Congress Street fire occurred just hours before Gov. Paul LePage and Maine Fire Marshal Joe Thomas spoke about fireworks safety at the recently opened Phantom Fireworks store in Scarborough.

“I’d like to know where the parents were,” said LePage, when asked about the fire in Portland.