Some government-run fuel stations have been ordered to operate around the clock to meet demand, the official news agency INA reported.

Dozens of vehicles were lined up at stations that remained open.

Some owners of petrol stations have denounced the method of fuel distribution imposed by the authorities, complaining they end up paying more for the quantity of fuel they receive from the government than what they say it is worth.

Iraq is the second largest producer in the Organization of the Petroleum Exporting Countries (OPEC), and oil provides more than 90 percent of its income.

But the country, with a population of about 41 million, is also grappling with a major energy crisis and regular power cuts.

In recent days, private stations had already suspended their activities in the southern city of Najaf, according to INA.

The government has played down the problem, saying it is limited to "certain stations" in the capital Baghdad and the central and southern provinces, said Ihsan Mussa Ghanem, deputy head of the Iraqi agency in charge of distributing petroleum products.

In a statement, his agency said the owners of the closed stations were "manufacturing crises and obstructing the distribution of gasoline to citizens".

Owners do not have the right to stop supplies, it said, and "inspection committees will identify all stations that contravene instructions."

Those that have shut their pumps face having their licenses suspended and supplies of oil stopped, the statement said.