The country’s national mining ​agency had weeks earlier warned that a buildup of gases at the mine could become dangerous. A coal mine explosion in Colombia’s Cundinamarca province killed nine workers and injured six, the National Mining Agency said, weeks after issuing risk-control recommendations for the site. The blast on Monday at a legally operated mine in the Sutatausa municipality, 72km (45 miles) north of the capital Bogota, was caused by a buildup of gases, the agency said. Recommended Stories list of 4 items list 1 of 4 Video: Colombia blames dissident FARC rebel for deadly bus bomb list 2 of 4 At least 20 killed in Colombia highway blast list 3 of 4 Car show turns to tragedy as monster truck drives into crowd in Colombia list 4 of 4 Photos: Bomb attack on Colombia highway kills 19 ahead of election end of list Colombia is home to numerous open and underground gold and coal mines.…