ALLENTOWN, Pa. – Multiple fire crews were called to a three alarm apartment building fire on Wednesday.

Allentown fire department says that a call came in just after 5:00 p.m. for a fire in the 600 block of North 22nd Street in Allentown.

First arriving units found flames from the roof of the structure, according to the Allentown Fire Department. 

By 6:04 p.m., the blaze became a three alarm fire, prompting a large response from multiple fire departments.

The additional alarms were due to the high temperature and to provide relief to those working on the fire, according to the department. 

The fire is under control, but crews remain on scene.

There were no injuries reported by residents or firefighters, the fire department said. 

The residents of all the units will be displaced for an unknown period of time, according to fire officials. 

The Red Cross was requested to assist the five adults displaced.

The cause of the fire is under investigation by the Fire Marshal division.