A powerful earthquake rocked Indonesia's Sulawesi island early Friday, killing at least 34 people, levelling a hospital and severely damaging other buildings, authorities said. Hundreds more were injured when the 6.2-magnitude quake struck in the early hours, triggering panic among the terrified residents of the island, which was hit by a huge quake and tsunami two and a half years ago that killed thousands. "The latest information we have is that 26 people are dead... in Mamuju city," said Ali Rahman, head of the local disaster mitigation agency, adding "that number could grow". "Many of the dead are buried under rubble," he said. Rescuers were searching for more than a dozen patients and staff trapped beneath the rubble of the levelled Mamuju hospital. "The hospital is flattened -- it collapsed," said Arianto from the rescue agency in Mamuju city, who goes by one name. "There are patients and hospital employees trapped under the rubble and we're now trying to reach them," he added, without giving a specific figure.