Rescue workers still cannot find the 33 Chilean workers who have been trapped in a copper mine for two weeks, dpa quoted Chilean President Sebastian Pinera as saying Thursday. The workers have been trapped since August 5 in a mine in San Jose de Copiapo, in the Atacama Desert, after the shaft they were working in collapsed. Several further collapses have frustrated rescue efforts since then, and the authorities, like most observers, unofficially express their fear that the miners may have died. "Only God can save them, I don't know what else can be done," Crisologo Rojas, the uncle of one of the trapped workers, told the German Press Agency dpa. The workers are believed to be in a shelter some 700 metres underground. However, all efforts to reach them, even through holes just a few centimetres in diameter to provide them with food and water, have so far failed. Pinera called upon his compatriots to "not lose hope" and vowed to bring those responsible for the mining disaster to justice. The accident, the worst of its kind in a decade in Chile, has prompted debate about working conditions for miners in small and medium-sized mining fields, which sometimes lack the necessary safety mechanisms.