Three coal officials have been detained and two others suspended from duty for allegedly detonating excessive explosives underground. The resulting gas blast killed 30 miners and injured 77 in Chongqing on Saturday. A safety official from Beijing who went to the scene immediately blamed human error. He said too much explosive was used for an expansion project, and the Tonghua Coal Mine officials did not move the 131 working miners to safety before the explosion, Xinhua reported. 'Coal mine owners put the emphasis on accelerating construction instead of work safety,' said Zhao Tiechui , head of the State Administration of Coal Mine Safety. 'The mine's managers didn't evacuate workers in time.' Apparently because of rising coal prices in recent years, the production capacity of the mine had been temporarily doubled, from the 300,000 tonnes a year stated in the contract when the colliery went into operation in 1958. According to cqnews.net, the news portal of the Chongqing Daily, local police detained three men yesterday - Chen Youming , chief engineer of the state-owned Songzao Mining Bureau of Chongqing; Liu Qiang , a project manager of the construction firm affiliated with the bureau; and Yi Zheng , the director of the mine. The report also said the State-owned Assets Supervision and Administration Commission of Chongqing municipality had yesterday suspended from duty Liu Mingyuan , the deputy general manager of Songzao, and Peng Zhiqiang , the board director and general manager of the construction firm. Both officials were being investigated for their roles in the explosion. The miners had been working 1km underground when the blast occurred at about 11am on Saturday. Dozens of their relatives who flocked to the scene after the explosion were waiting anxiously outside the entrance to the colliery. One middle-aged woman told a reporter with China National Radio yesterday morning that there was no news about her husband, who was working underground. She said her husband was the only one working to support the family, which also included a senior and a child. Another miner, Wang Ming , called himself the 'luckiest miner' for taking the day off after having worked overnight. 'Just like most of my fellow colleagues, I am employed by private project contractors even though I'm working for a state-owned mine,' he said. This was the mainland's most serious mine accident in nearly four months, since a blast in Shanxi province took 74 miners' lives in late February. By yesterday afternoon, all the wounded had received treatment at a local hospital. China News Service reported that at least one of the families had accepted 270,000 yuan (HK306,500) in compensation.