NEW YORK (CBSNewYork) – Firefighters battled a stubborn recycling plant fire overnight in the Bronx.

Flames broke out around 12:30 a.m. Thursday near East 136th Street and Walnut Avenue in the Port Morris section.

It took crews more than three hours to get the fire under control.

At least five firefighters suffered non-life-threatening injuries. No civilians were hurt.

The cause of the blaze is under investigation.