Firefighters are battling heavy flames Friday morning in the Allerton section of the Bronx.

Citizen app footage showed the scene of the fire as neighbors gather to watch the smoke and flames pour out of the three-story apartment building.

Officials say the fire started on the first floor around 12:45 a.m. Firefighters were able to get the blaze under control at 3:30 a.m.

Three people were reportedly injured but refused medical attention.

The cause of the fire is still being investigated.