Privately held operator Zone Energy of Houston reported a “flash fire” on Monday to the Texas Railroad Commission.
The blast occurred in the Laird Hill region south of Kilgore, Texas, at around 19:30 Monday night, Commission spokeswoman Ramona Nye said in a statement.
“The operator reported the flash fire at the vacuum truck occurred as they were working on their well site,” Nye said. “The oil well was not involved in this reported fire,” she added.
No other details were available about the operations at the wellsite at the time of the blast. Houston-based Zone did not respond to a request for comment on Friday. The Kilgore Fire Department, which responded to the blaze, also did not return calls for comment.
Four workers were hospitalised as a result of the blast, and at least two of them were “critically burned”, according to local reports. None of the injuries were considered life threatening, however
The US Occupational Safety & Health Administration is investigating the incident, Nye said.