CHICAGO (STMW) — Crews are battling an extra-alarm fire Wednesday morning at an apartment building in the Northwest Side Portage Park neighborhood.

The two-alarm fire broke out in the three-story building at 3234 N. Central Ave. at 7:09 a.m., according to Fire Media Affairs. The building contains four businesses on the first floor and 12 apartments on the upper floors.

The first companies arrived at the scene four minutes later, and saw several residents on the balconies of their upper-floor units, according to Fire Media. Firefighters used ladders to rescue them.

The fire was upgraded to a second alarm at 7:37 a.m., according to Fire Media. About 110 firefighters were fighting the blaze.

No injuries have been reported.

No. 85 Central buses are rerouted in both directions in the area of the fire, according to a CTA alert.

(Source: Sun-Times Media Wire © Chicago Sun-Times 2016. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)