Fifty-four people were injured, and another 18 were missing after an explosion at Qatar's core LNG processing site of Ras Laffan on Sunday, Qatar's Interior Ministry said in a statement.
An incident during the start-up of operations at Ras Laffan Industrial City resulted in an explosion and fire at the Barzan local gas supply facility on Sunday evening, QatarEnergy said in a statement.
Emergency response teams were deployed to contain the fire, which was now under control, it said.
The interior ministry attributed the explosion to a "technical accident" and said there was no leak that posed a threat to public safety.
It said the Qatari International Search and Rescue Group, in cooperation with the civil defense teams, was conducting search operations for the 18 missing people.
A loud boom followed by fire, many feared dead
QatarEnergy did not indicate whether the explosion had caused any damage to the plant, which supplies gas to the domestic market.
A Reuters witness earlier reported that a loud boom was heard in the capital Doha, south of the Ras Laffan facility.