Qatar's state-run energy firm announced on Monday it had stopped liquefied natural gas (LNG) production following Iranian attacks on facilities at two of its main gas processing bases.

"Due to military attacks on QatarEnergy's operating facilities in Ras Laffan Industrial City and Mesaieed Industrial City in the State of Qatar, QatarEnergy has ceased production of liquefied natural gas (LNG) and associated products," the company said in a statement.

Earlier, Qatar's Defence Ministry said one Iranian drone "targeted an energy facility in Ras Laffan Industrial City, belonging to QatarEnergy," referring to the firm's onshore gas processing base 80 kilometres (50 miles) north of Doha.

Another "targeted a water tank belonging to a power plant in Mesaieed," the statement said, referring to an area 40 kilometres south of the Qatari capital, which is also a key site for Qatar's natural gas production.

There were no reports of casualties, the ministry added.

The Gulf state is one of the world's top liquefied natural gas producers, alongside the United States, Australia and Russia.

Qatar shares the world's largest natural gas reservoir with Iran.

State-run QatarEnergy estimates the Gulf state's portion of the reservoir, the North Field, holds about 10% of the world's known natural gas reserves.

In recent years, Qatar has inked a series of long-term LNG deals with France's Total, Britain's Shell, India's Petronet, China's Sinopec and Italy's Eni, among others.