Train carrying iron ore derails in San Bernardino County, California

A train carrying raw material derailed in California on Monday, according to San Bernardino County fire officials. There were no passengers on the Union Pacific train, but multiple cars containing iron ore derailed, officials said.

According to Union Pacific officials, 55 train cars, including two locomotives, derailed at 8:30 a.m., local time.

One locomotive suffered a minor leak, which is being investigated by hazmat officials, county fire officials said.

There were no injuries and no active fires, as well as no threat to the public or the environment, San Bernardino County Fire tweeted.

In a statement to ABC News, Union Pacific confirmed that the derailed cars did have iron ore, which spilled, but that it isn't hazardous and that there were no hazardous materials on the train.

"The crew was not in the cab at the time of the derailment and there was uncontrolled train movement," Union Pacific said in a statement. "The crew was not injured."

The derailment is currently being investigated, Union Pacific said.

The incident comes more than a month after a Norfolk Southern foreign train derailed in East Palestine, Ohio, releasing vinyl chloride, ethyl acrylate and isobutylene into the environment.

Norfolk Southern officials had conducted a controlled burn of toxic chemicals from the train a few days after the derailment, which worried residents who expressed concerns they were exposed to high levels of the colorless gas vinyl chloride, which easily burns and is associated with an increased risk of several cancers, according to the National Cancer Institute.

Earlier this month, 28 cars of another Norfolk Southern train derailed near Springfield, Ohio, but no hazardous materials were involved, officials said.

The four empty tankers were previously carrying diesel exhaust fluid and an additive commonly used in wastewater treatment, according to Clark County, Ohio officials.

According to the United States Geological Survey, iron ore is important for steel production as it is the source of primary iron for steel and iron industries around the world.

In December, a Union Pacific freight train carrying iron ore derailed in Southern California, according to the Associated Press. There were no reported injuries.

ABC News' Matthew Fuhrman contributed to this report.