HOUSTON -

A warehouse fire in East Harris County had firefighters battling flames for nearly four and a half hours.

Crews from the Cloverfield Fire Department were called to the 13600 block of Industrial Road around 12:30 p.m. Saturday when flames were seen billowing out of the Texas Distribution, Inc. warehouse.

The fire was originally called in as a two-alarm blaze, but fire officials said they soon escalated it to a five alarm.

"When they got on scene, they realized it was going to be a little bigger than what we had," Doug Clough of the Cloverleaf Fire Department said.

Several people who were nearby said they heard a loud explosion before the warehouse went up in flames.

In all, officials said as many as 140 firefighters from various stations converged on the export packing company that bags and blends specialized products, according to Texas Distribution Inc.'s website.

Investigators don't believe hazardous materials were burned.

The fire was tapped out just before 5:00 p.m., but officials said fire crews remained on the scene putting out hot spots.

No injuries were reported, and no shelter in place was issued.

The source of the fire is still under investigation.