Dozens of people were displaced after flames ripped through a large three-story apartment building Thursday night near the Reading line in Muhlenberg Township.

Muhlenberg Township Fire & Rescue was dispatched about 9 p.m. to the Oak Forest apartments complex on Hampden Boulevard. The first crew to arrive confirmed the third floor of the complex at 2271 Hampden Blvd. was on fire, with flames running along the roof.

Crews initially mounted an interior attack but were forced to evacuate from the third floor after the roof partially collapsed. Firefighters pounded the flames with water from aerial ladder trucks.

No injuries were reported.

While an exact number of displaced residents was unavailable, a Red Cross spokeswoman said a disaster assistance team arrived overnight to assist impacted residents.

As of about noon Friday, the Red Cross had helped 21 people, including four children, said Cristina Maisel, regional communications manager for the American Red Cross Greater Pennsylvania Region

“Our volunteers are continuing to connect with additional displaced residents today to offer our services,” Maisel said in an email. “Anyone in need of Red Cross assistance should call 1-800-RED CROSS (1-800-733-2767).

“The Red Cross is also working closely with local partners to create plans and coordinate recovery services to ensure people get the help they need to get back on their feet.”