LA PORTE, Texas (AP) -- Firefighters were battling a massive pipeline fire in suburban Houston that sparked grass fires and burned power poles on Monday, forcing people in the surrounding neighborhood to evacuate as a giant plume of fire was shooting high up into the air.

The fire began at 9:55 a.m. in La Porte, located about 25 miles (40 kilometers) southwest of Houston.

La Porte City Secretary Lee Woodward told KTRK-TV that they don't yet know what flows through the pipeline or how it will be shut down.

Video images from KTRK showed a park near the fire had been damaged and firefighters pouring water on adjacent homes. There are also several businesses nearby, including a Walmart.

Officials have ordered residents in the Brookglen neighborhood area near the fire to evacuate, Lee Woodward, a La Porte city spokesperson said in an email.

"Please avoid the area and follow law enforcement direction. Further details will be released as available," Woodward said.

The cause of the fire was not immediately known.

There are several power lines near the fire. The website PowerOutage.us says that there are nearly 4,700 customers without power in Harris County.

CenterPoint Energy said it is monitoring the fire, which is near Spencer Highway in LaPorte. The company said the fire "is unrelated to the company's natural gas operations or equipment."

"We are also cooperating with first responders. Putting safety first, the public should avoid this area until further notice from local emergency officials. When it is safe to do so, our electric crews will go into the area to assess the damage to our transmission and distribution power lines, poles and equipment and begin restoring service to impacted customers as safely and quickly as possible."