Explosion kills three workers at Parsley Energy Texas oil rig
This August 21, 2013 photo shows an oil well near Tioga, North Dakota (AFP Photo/Karen Bleier)

An explosion has killed three people and injured one at an oil and gas field in West Texas, a spokesman for well owner Parsley Energy Inc. said on Wednesday.

"Our thoughts are with the families," Lisa Elliott of Parsley said of the accident on Tuesday in Upton County, Texas.

The Occupational Safety and Health Administration said it was investigating the rig explosion about 50 miles south of Midland that involved contractors at Mason Well Service firm.

Upton County's Office of Emergency Management, via social media, called the news sad and said few details were available.

Parsley is one of many small companies working in the Permian Basin of Texas, one of the top U.S. shale oil fields.

There have been numerous deadly rig explosions in the United States over the last decade. Wells can blow out when drilling rigs are overwhelmed by pressure from underground.

(Reporting By Reuters Energy Desk; Editing by David Gregorio)