Philippine Energy Secretary Jericho Petilla has said it may take six weeks before the first typhoon-hit towns get their electric power back.
Speaking at Cebu airport on Wednesday night, Petilla said many transmission lines had been toppled and power plants damaged from Typhoon Haiyan.
Petilla said that in the hard-hit coastal city of Tacloban, order needed to be restored "because if there's no peace and order, it's hard to reinstall the power posts."
He said army troops had fired shots Wednesday to drive away a group of armed men who approached a power transmission sub-station in Leyte province.
The unidentified men fired back then fled. Nobody was hurt.
Panic is mounting in the Philippines, with minimal food and medical supplies reaching areas worst hit by the typhoon, reports of civil order breaking down and the number of unburied dead threatening the health of survivors.
Cabinet Secretary Rene Almendras on Wednesday said the government had been overwhelmed by the sheer number of victims that need to be buried.
The UN estimated that 10,000 people may have died in Tacloban alone, where five-metre waves flattened nearly everything in their path. President Benigno Aquino, however, said the death toll was no more than 2,500 people.
Five days after Haiyan ripped apart entire coastal communities, authorities in Tacloban, Leyte's provincial capital, struggled to dispose of the dead.
"The reason the body recovery stopped is because we ran out of body bags," Almendras said. "But we now have 4,000 bags. I am not saying the casualties are 4,000. We are making sure there is an oversupply."
Attempts on Wednesday to bury some of the victims suffered a setback when gunshots halted a convoy travelling towards a communal grave.
"We had finished digging the mass burial site. We had the truck loaded with bodies... but... there was some shooting," Tacloban mayor Alfred Romualdez told the AFP news agency. "They could not proceed."
Adding to the grim body count, news emerged that eight people were crushed to death a day earlier when a huge crowd of survivors from the typhoon rushed a government rice store.
"One wall of our warehouses collapsed and eight people were crushed and killed instantly," the National Food Authority's Rex Estoperez said of the incident in Alangalang town, 17 kilometres from Tacloban.
Increasingly desperate survivors on Wednesday clamoured to leave the Tacloban, jostling and begging for seats on scarce flights. Philippines Airlines said it was laying on six planes a day, each with 75 seats.
"Everyone is panicking," Captain Emily Chang, a navy doctor, told AFP. "They say there is no food, no water. They want to get of here," she added, saying doctors at the airport had run out of medicine, including antibiotics.
"We are examining everyone but there's little we can do until more medical supplies arrive."
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The World Health Organisation said there were significant injuries that needed to be dealt with, even as medics worked to prevent outbreaks of disease caused by cramped living conditions and dirty drinking water.
It cautioned regular health needs also had to be met, including the 12,000 babies expected to be born this month to the more than 11.3 million people affected.
Overwhelmed and under-resourced rescue workers have been unable to provide food, water, medicines, shelter and other relief supplies to some of the 673,000 made homeless, and desperation has been growing across the disaster zones.
"People are desperate because they have nothing in Tacloban," Marco Boasso of the International Organisation for Migration said.
Hundreds of soldiers and police were patrolling the streets and manning checkpoints in Tacloban to try to prevent pillaging and the government said roads were now passable throughout the area, raising hope that relief might finally reach those in need.
But a curfew was coming into force again on Wednesday evening as troops fanned out to preserve order in the dark.