Six miners were killed and three more were injured on Thursday when the roof of a coal mine collapsed in western Georgia, officials said. The accident happened at the Mindeli mine in the city of Tqibuli, 200 km west of the capital Tbilisi, early Thursday, the office of Georgian Prime Minister Giorgi Kvirikashvili said in a statement. "Six people died in the accident and three other miners were injured," the statement said. The government blamed so-called "rock burst" -- a spontaneous, violent fracture of rock that can occur in mines -- for the accident, adding that an investigation had been launched to determine whether safety norms had been breached. The mine is operated by Sakhnakhshiri, a Georgian company. Ten miners have died at the mine in different accidents since 2011. According to Georgias interior ministry, more than 350 people were killed and more than 900 more injured in occupational accidents in the country between 2010 and 2017.