HOUSTON (Reuters) - An Enogex-owned natural gas pipeline exploded on Tuesday about 50 miles southwest of Oklahoma City, Oklahoma, injuring three people, officials said.

The explosion occurred about 5 miles west of Pocasset about 10:50 a.m. CDT (1550 GMT), Grady County Emergency Management Director, Dale Thompson said.

Enogex is a unit of OGE. The incident occurred

on a 20-inch-diameter gathering line serving a processing plant in Cox City, Oklahoma.

A crew was performing maintenance on the line at the time of the explosion, the company said.

The fire weakened by midday after valves on the line were shut to stop the flow, Thompson said.

(Reporting by Bruce Nichols and Ed McAllister; Editing by Sofina Mirza-Reid)