VIDEO: Shootout captured on camera in northwest Harris County

HOUSTON (KTRK) -- Two robbery suspects are on the run after a Wild West-style shootout at a northwest Harris County gas station last night.

An off-duty police officer stopped at the Shell station on Highway 6 near 290 at around 9pm, reportedly in the middle of a robbery.

When the Tomball officer pulled into the parking lot, the suspects in ski masks were leaving. He ordered the suspects to freeze. Instead, they opened fire, even though there were several innocent bystanders. The officer returned fire.

Harris County Sheriff's Office spokesman Thomas Gilliland said, "They exchanged a lot of gunfire, probably anywhere from 15 to 20 rounds were fired between the two areas."

The suspects fled. Authorities found a stolen truck abandoned at a nearby apartment complex. The truck had blood inside. They used helicopter and K-9 units to search for the suspects, but did not find them.

If you have any information, contact police.