Hospitals in the Akkar region of north Lebanon where a fuel tank explosion killed at least 28 people this week struggled to operate on Tuesday as life-threatening power cuts and telecom outages swept the area.

Lights and phone lines went out across the impoverished and marginalised region that has long suffered from an ailing power grid but that is now grappling with an unprecedented crisis due to severe diesel shortages nationwide.

The outages come less than two days after a fuel tank exploded in the village of Al Tleil, scorching people clamouring to fill petrol that the army was distributing.

Around 80 people, including several soldiers, were injured, many of them left with severe burns, overwhelming hospitals.

Fuel shortages since the start of summer have aggravated hardship in Lebanon, a country of more than 6 million that is in the throes of an economic crisis branded by the World Bank as one of the worst since the mid-19th century.

Without the diesel fuel needed to power private generators, businesses, hospitals and even the country's main telecom operator have been forced to scale back operations or close entirely due to outages lasting up to 22 hours a day.

In Akkar, hospitals still storing corpses of victims charred in Sunday's blast were left without power, internet and working landlines, as health officials pleaded for help from the authorities.

"We have a stock of 700 litres of diesel fuel which will last for only one day," said Riad Rahal, director of Rahal Hospital in the Akkar town of Halba.

The nearby El-Youssef hospital also had enough stock of diesel to last until Wednesday morning and no working phone lines, said Nathaline el-Chaar, assistant to the director.

"Since yesterday, landlines have been out of service... and we are trying hard to secure diesel," she told AFP.

She said the hospital's diesel provider had delayed deliveries fearing attacks on a north Lebanon highway where incidents in recent days have seen angry groups seize fuel from trucks.

The official National News Agency said on Tuesday that diesel fuel shortages and power outages had forced the Ogero telecom provider to cut internet, landlines and mobile phone services in several parts of Akkar, effectively paralysing banks, businesses and state offices.

Ogero head Imad Kreidieh warned that other regions in Lebanon would have to follow suit unless the situation improved.

In the southern suburbs of Beirut, live shots were fired at a gas station, the latest in a series of lethal incidents rattling motorists lining up in long petrol queues.

The NNA said the army deployed in the area after several people were injured in the shoot-out, but it did not provide more details.

A security source told AFP that people who had illegally stored petrol at a pumping station fired live rounds as army soldiers tried to confiscate their stock.

They also started a fire at the gas station, accusing its owner of having tipped off the army.

Videos and pictures circulating on social media showed men opening machine-gun fire. AFP could not independently verify the authenticity of the footage.

The army on Saturday started raiding gas stations and confiscating stocks of fuel that distributors have been hoarding to sell at a higher price in the black market or across the border in Syria.