SOMA, Turkey (AP) — In a relentless procession that ignited wails of grief and flashes of anger, rescue workers coated in grime lumbered out of a mine in western Turkey again and again Wednesday, struggling to carry bodies covered in blankets.

The corpses’ faces were as black as the coal they worked on daily. There were 274 of them — and the fate of up to 150 other miners remained unclear in Turkey’s deadliest-ever mining disaster.

While emergency workers battled a toxic mix of carbon dioxide and carbon monoxide in deep tunnels, anger and despair engulfed the town of Soma, where Turkish officials said at least 274 miners died in Tuesday’s coal mine explosion and fire.

Prime Minister Recep Tayyip Erdogan was heckled as he tried to show concern and anti-government protests erupted in Soma, Istanbul and Ankara, the capital. Erdogan had to seek refuge in a supermarket, surrounded by police, then leave in a black car after the protest in Soma died down. He also did little for his reputation by noting that workplace accidents are “ordinary things” that happen in many countries.

The display of anger could have significant repercussions for Erdogan, who is widely expected to run for president in the August election, although he has not yet announced his candidacy.  

Tensions were high as hundreds of relatives and miners jostled outside the mine’s entrance Wednesday, waiting for news amid a heavy police presence. Rows of women wailed uncontrollably and men knelt sobbing or simply stared in disbelief as rescue workers removed body after body.

Energy Minister Taner Yildiz said 787 people had been inside the coal mine at the time of Tuesday’s explosion: 274 had died, 363 had been rescued and scores of them were injured.

The death toll topped a 1992 gas explosion that killed 263 workers near Turkey’s Black Sea port of Zonguldak. It also left 150 miners unaccounted for.

Erdogan said Wednesday morning that 120 miners were still missing. There was no immediate way to reconcile the differing figures.  

Rescuers were still trying to vent out the carbon dioxide and carbon monoxide and pump clean air into the mine, according to mine owner Soma Komur Isletmeleri A.S.

Some workers had been up to 460 yards deep inside the mine, Yildriz said. One rescue worker who declined to be named said he had led a 10-man team about a kilometer down into the mine’s tunnels. They recovered three bodies but had to quickly turn around and flee because of smoke from burning coal.

The last worker rescued alive emerged from the mine around dawn and the first burials took place later Wednesday. Rescue operations were halted for several hours into Thursday morning because high gas concentrations in the mine needed to be cleared.

Giza Nergiz, a 28-year-old English teacher, said some of the workers who died had complained about safety at the mine.

“We buried three of our high school friends today,” she said, walking with her husband Onur Nergiz, a 30-year-old mine administrator.

 “A lot of people were complaining about safety, but nobody (in management) was doing anything about it.”

Erdogan had declared three days of national mourning and postponed a trip to Albania to visit the mine in Soma, about 250 kilometers (155 miles) south of Istanbul. He had warned that some radical groups would try to use the disaster to discredit his government.

“Our hope is that, God willing, they will be brought out,” Erdogan said of those still trapped. “That is what we are waiting for.”

Yet his efforts to appear statesman-like — discussing rescue operations with authorities, walking near the mine entrance, trying to comfort two crying women — did not go over well. And some of his statements appeared completely tone-deaf.

“These are ordinary things. There is a thing in literature called ‘work accident’... It happens in other work places, too,” Erdogan told reporters as he tried to deflect a question about who was responsible for the disaster. “It happened here. It’s in its nature. It’s not possible for there to be no accidents in mines. Of course we were deeply pained by the extent here.”

In this industrial town, where coal mining has been the main industry for decades, Erdogan’s ties to mining leaders were sharply noted. Locals said the wife of the Soma mine’s boss reportedly works for Erdogan’s party and the boss himself had skipped town.

“They are trying to look like they care but they are not helping anyone. There is no urgency, even now. People blame Tayyip,” Giza Nergiz said Wednesday.

In downtown Soma, protesters mostly in their teens and 20s faced off against riot police in front of the ruling NKP party headquarters. The protesters smashed some of the party’s office windows with rocks, shouting that Erdogan was a “Murderer!” and a “Thief!”

“Our prime minister is a dictator,” said protester Melih Atik, 16. “Neither the government nor the company took precautions in the mine and everyone knows that’s why this happened.”

Erdogan was forced to oust four ministers from his government in December after they were implicated in a police bribery and corruption probe. The scandal deepened after a series of audio recordings were posted on the Internet suggesting corruption by the prime minister and his family members. Erdogan denies corruption and says the allegations are a plot to discredit his government.

In Istanbul, hundreds of demonstrators gathered outside the headquarters of mine owner Soma Komur Isletmeleri A.S. Police used tear gas and water cannon to break up a group who tried to march to the city’s iconic Taksim Square to denounce poor safety conditions.

Police also dispersed a group marching to the energy ministry in Ankara to protest the deaths.

Fences were erected and police also stood guard around Soma hospital, which was treating scores of injured miners. Some locals said the men were being pressured by the mining company not to talk about the blast.

Authorities say the disaster followed an explosion and fire at a power distribution unit and the deaths were caused by carbon monoxide poisoning. Erdogan promised the tragedy would be investigated to its “smallest detail” and that “no negligence will be ignored.”

Mining accidents are common in Turkey, which is plagued by poor safety conditions. Tuesday’s explosion tore through the mine during a shift change, which likely raised the casualty toll.

Turkey’s Labor and Social Security Ministry said the mine had been inspected five times since 2012, including two months ago in March, and that no issues violating work safety and security were detected. But the country’s main opposition party said Erdogan’s ruling party had recently voted down a proposal to hold a parliamentary inquiry into a series of small-scale accidents at the mines around Soma.

Emine Gulsen sat with other women Wednesday near the entrance to the mine, where her missing son, 31-year-old Mehmet Gulsen, has worked for five years.

“My son is gone! My Mehmet!” she wailed over and over.

But Mehmet’s aunt, Makbule Dag, still held out some hope.

“Inshallah (God willing)” he will be rescued, she said.