Anger and grief boiled over into violent protests across Turkey, as officials announced at least 274 miners died in an explosion and fire in the town of Soma - the country's deadliest mining disaster.Nearly 450 other miners have been rescued, the mining company said, but the fate of an unknown number of others remained unclear.Mass graves were being dug in the town, as it prepared to bury those who were brought to the surface by nightfall, in line with Muslim tradition.Tensions were high as hundreds of relatives and miners jostled outside the coal mine waiting for news, countered by a heavy police presence.  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 the party's office windows with rocks and some in the crowd shouted that Prime Minister Recep Tayyip Erdogan was a 'murderer!' and a 'thief!' . And in Istanbul, hundreds of demonstrators gathered outside the headquarters of mine owner Soma Komur Isletmeleri A.S.The rise in death toll to 274 makes this the worst mining tragedy in Turkey's history . Until now, the worst mining disaster was in 1992, when 263 miners were killed near Zonguldak, on the Black Sea. 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, the Dogan news agency reported. 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. 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 as workers were preparing for a shift change, which likely raised the casualty toll.In Soma, rows of women wailed uncontrollably, men knelt sobbing and others just stared in disbelief as rescue workers removed a steady stream of bodies throughout the night and early morning. Others shouted at Turkish officials as they passed by.Officials said the explosion tore through the mine as workers were preparing for a shift change, which is likely to have raised the casualty toll because there were more miners inside than usual.The last worker rescued alive emerged from the mine around dawn, a government official said on condition of anonymity because she didn't have prior authorization to speak publicly to journalists about the issue. As of 3.30pm, it had been about 10 hours since anyone had been brought out alive.In the capital, Ankara, police dispersed a group who tried to march to the energy ministry to protest the deaths, the Dogan news agency reported.Erdogan had warned that some radical groups would try to use the disaster to discredit the government. Erdogan himself is widely expected to run for president in elections in August, although he has not yet announced his candidacy.Erdogan had declared three days of national mourning and ordered flags to be lowered to half-staff after the tragedy struck Tuesday. He postponed a foreign trip to visit the mine in Soma, about 250 kilometers (155 miles) south of Istanbul.'Our hope is that, God willing, they will be brought out,' he said of those still trapped.'That is what we are waiting for.'Erdogan said the tragedy would be investigated to its ‘smallest detail’ and ‘no negligence will be ignored.’He discussed rescue operations with authorities, walked near the entrance of the mine and also comforted two crying women. Earlier, Erdogan declared three days of national mourning, ordering flags to be lowered to half-staff.Energy Minister Taner Yildiz said 787 people were inside the coal mine in Soma at the time of Tuesday's explosion and 363 of them had been rescued. Scores were injured, Yildiz told reporters in Soma, where he was overseeing operations by more than 400 rescuers.‘Regarding the rescue operation, I can say that our hopes are diminishing,’ Yildiz said before Erdogan's visit.Erdogan said there were an estimated 120 workers still inside the mine.‘Our hope is that, God willing, they will be brought out,’ he said. ‘That is what we are waiting for.’Tensions were high as hundreds of relatives and miners stood outside the mine. The crowd shouted at officials, including when Yildiz passed by, and some wailed each time a body was brought up. A heavy police presence was in place around the mine.Mining accidents are common in Turkey, which is plagued by poor safety conditions. Turkey's worst mining disaster was a 1992 gas explosion that killed 263 workers near the Black Sea port of Zonguldak.(dailymail.co.uk)Bakudaily.az